diff --git a/Makefile.am b/Makefile.am
index 5fe2b1d42..ae51964fe 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -82,7 +82,7 @@ libgromox_email_la_LIBADD = ${fmt_LIBS} ${HX_LIBS} ${jsoncpp_LIBS} ${ssl_LIBS} $
 libgromox_epoll_la_CXXFLAGS = ${libgromox_common_la_CXXFLAGS}
 libgromox_epoll_la_SOURCES = lib/contexts_pool.cpp lib/threads_pool.cpp
 libgromox_epoll_la_LIBADD = -lpthread libgromox_common.la
-libgromox_exrpc_la_SOURCES = lib/exmdb_client.cpp lib/exmdb_ext.cpp lib/exmdb_rpc.cpp lib/ruleproc.cpp
+libgromox_exrpc_la_SOURCES = lib/exmdb_client.cpp lib/exmdb_ext.cpp lib/exmdb_rpc.cpp lib/freebusy.cpp lib/ruleproc.cpp
 libgromox_exrpc_la_LIBADD = libgromox_mapi.la
 libgromox_mapi_la_CXXFLAGS = ${libgromox_common_la_CXXFLAGS}
 libgromox_mapi_la_SOURCES = lib/mapi/eid_array.cpp lib/mapi/element_data.cpp lib/mapi/html.cpp lib/mapi/idset.cpp lib/mapi/lzxpress.cpp lib/mapi/msgchg_grouping.cpp lib/mapi/oxcical.cpp lib/mapi/oxcmail.cpp lib/mapi/oxvcard.cpp lib/mapi/pcl.cpp lib/mapi/proptag_array.cpp lib/mapi/propval.cpp lib/mapi/restriction.cpp lib/mapi/restriction2.cpp lib/mapi/rop_util.cpp lib/mapi/rtf.cpp lib/mapi/rtfcp.cpp lib/mapi/rule_actions.cpp lib/mapi/sortorder_set.cpp lib/mapi/tarray_set.cpp lib/mapi/tnef.cpp lib/mapi/tpropval_array.cpp
@@ -327,7 +327,7 @@ tzd_files = data/AUS_Central.tzd data/AUS_Eastern.tzd data/Afghanistan.tzd data/
 tzd_files += data/Haiti.tzd data/Hawaiian.tzd data/India.tzd data/Iran.tzd data/Israel.tzd data/Jordan.tzd data/Kaliningrad.tzd data/Korea.tzd data/Libya.tzd data/Line_Islands.tzd data/Lord_Howe.tzd data/Magadan.tzd data/Magallanes.tzd data/Marquesas.tzd data/Mauritius.tzd data/Middle_East.tzd data/Montevideo.tzd data/Morocco.tzd data/Mountain.tzd data/Mountain__Mexico_.tzd data/Myanmar.tzd data/N__Central_Asia.tzd data/Namibia.tzd data/Nepal.tzd data/New_Zealand.tzd data/Newfoundland.tzd data/Norfolk.tzd data/North_Asia.tzd data/North_Asia_East.tzd data/North_Korea.tzd data/Omsk.tzd data/Pacific.tzd data/Pacific_SA.tzd data/Pacific__Mexico_.tzd data/Pakistan.tzd data/Paraguay.tzd data/Qyzylorda.tzd data/Romance.tzd data/Russia_Time_Zone_10.tzd data/Russia_Time_Zone_11.tzd data/Russia_Time_Zone_3.tzd data/Russian.tzd
 tzd_files += data/SA_Eastern.tzd data/SA_Pacific.tzd data/SA_Western.tzd data/SE_Asia.tzd data/Saint_Pierre.tzd data/Sakhalin.tzd data/Samoa.tzd data/Sao_Tome.tzd data/Saratov.tzd data/Singapore.tzd data/South_Africa.tzd data/South_Sudan.tzd data/Sri_Lanka.tzd data/Sudan.tzd data/Syria.tzd data/Taipei.tzd data/Tasmania.tzd data/Tocantins.tzd data/Tokyo.tzd data/Tomsk.tzd data/Tonga.tzd data/Transbaikal.tzd data/Turkey.tzd data/Turks_And_Caicos.tzd data/US_Eastern.tzd data/US_Mountain.tzd data/UTC+12.tzd data/UTC+13.tzd data/UTC-02.tzd data/UTC-08.tzd data/UTC-09.tzd data/UTC-11.tzd data/UTC.tzd data/Ulaanbaatar.tzd data/Venezuela.tzd data/Vladivostok.tzd data/Volgograd.tzd data/W__Australia.tzd data/W__Central_Africa.tzd data/W__Europe.tzd data/W__Mongolia.tzd data/West_Asia.tzd data/West_Bank.tzd data/West_Pacific.tzd data/Yakutsk.tzd data/Yukon.tzd data/_GMT_+01_00_.tzd
 header_files = include/gromox/ab_tree.hpp include/gromox/arcfour.hpp include/gromox/atomic.hpp include/gromox/authmgr.hpp include/gromox/binrdwr.hpp include/gromox/bounce_gen.hpp include/gromox/clock.hpp include/gromox/common_types.hpp include/gromox/config_file.hpp include/gromox/contexts_pool.hpp include/gromox/cookie_parser.hpp include/gromox/cryptoutil.hpp include/gromox/database.h include/gromox/database_mysql.hpp include/gromox/dbop.h include/gromox/dcerpc.hpp include/gromox/defs.h include/gromox/double_list.hpp include/gromox/dsn.hpp include/gromox/eid_array.hpp include/gromox/element_data.hpp include/gromox/endian.hpp include/gromox/exmdb_client.hpp include/gromox/exmdb_common_util.hpp include/gromox/exmdb_ext.hpp include/gromox/exmdb_idef.hpp include/gromox/exmdb_provider_client.hpp include/gromox/exmdb_rpc.hpp include/gromox/exmdb_server.hpp include/gromox/ext_buffer.hpp
-header_files += include/gromox/fileio.h include/gromox/flusher_common.h include/gromox/generic_connection.hpp include/gromox/hook_common.h include/gromox/hpm_common.h include/gromox/html.hpp include/gromox/ical.hpp include/gromox/icase.hpp include/gromox/int_hash.hpp include/gromox/json.hpp include/gromox/list_file.hpp include/gromox/lzxpress.hpp include/gromox/mail.hpp include/gromox/mail_func.hpp include/gromox/mapi_types.hpp include/gromox/mapidefs.h include/gromox/mapierr.hpp include/gromox/mapitags.hpp include/gromox/mem_file.hpp include/gromox/midb.hpp include/gromox/mime.hpp include/gromox/mime_pool.hpp include/gromox/mjson.hpp include/gromox/msg_unit.hpp include/gromox/msgchg_grouping.hpp include/gromox/mysql_adaptor.hpp include/gromox/ndr.hpp include/gromox/ntlmssp.hpp include/gromox/oxcmail.hpp include/gromox/oxoabkt.hpp
+header_files += include/gromox/fileio.h include/gromox/flusher_common.h include/gromox/freebusy.hpp include/gromox/generic_connection.hpp include/gromox/hook_common.h include/gromox/hpm_common.h include/gromox/html.hpp include/gromox/ical.hpp include/gromox/icase.hpp include/gromox/int_hash.hpp include/gromox/json.hpp include/gromox/list_file.hpp include/gromox/lzxpress.hpp include/gromox/mail.hpp include/gromox/mail_func.hpp include/gromox/mapi_types.hpp include/gromox/mapidefs.h include/gromox/mapierr.hpp include/gromox/mapitags.hpp include/gromox/mem_file.hpp include/gromox/midb.hpp include/gromox/mime.hpp include/gromox/mime_pool.hpp include/gromox/mjson.hpp include/gromox/msg_unit.hpp include/gromox/msgchg_grouping.hpp include/gromox/mysql_adaptor.hpp include/gromox/ndr.hpp include/gromox/ntlmssp.hpp include/gromox/oxcmail.hpp include/gromox/oxoabkt.hpp
 header_files += include/gromox/paths.h.in include/gromox/pcl.hpp include/gromox/plugin.hpp include/gromox/proc_common.h include/gromox/proptag_array.hpp include/gromox/propval.hpp include/gromox/range_set.hpp include/gromox/resource_pool.hpp include/gromox/restriction.hpp include/gromox/rop_util.hpp include/gromox/rpc_types.hpp include/gromox/rtf.hpp include/gromox/rtfcp.hpp include/gromox/rule_actions.hpp include/gromox/safeint.hpp include/gromox/scope.hpp include/gromox/simple_tree.hpp include/gromox/sortorder_set.hpp include/gromox/stream.hpp include/gromox/svc_common.h include/gromox/svc_loader.hpp include/gromox/textmaps.hpp include/gromox/threads_pool.hpp include/gromox/tie.hpp include/gromox/timezone.hpp include/gromox/tnef.hpp include/gromox/util.hpp include/gromox/vcard.hpp include/gromox/xarray2.hpp include/gromox/zcore_client.hpp include/gromox/zcore_rpc.hpp include/gromox/zz_ndr_stack.hpp
 dist_pkgdata_DATA = ${abkt_files} ${tzd_files}
 toolprogs = tools/defs2php.pl tools/defs2php.sh tools/duplogid tools/enumsort tools/exmidl.pl tools/exmidl.sh tools/includesort tools/proptagsort tools/stackusage tools/warncount tools/zcidl.pl tools/zcidl.sh
diff --git a/exch/zcore/names.cpp b/exch/zcore/names.cpp
index 074686021..14212e9e2 100644
--- a/exch/zcore/names.cpp
+++ b/exch/zcore/names.cpp
@@ -100,7 +100,8 @@ static constexpr const char *zcore_rpc_names[] = {
 	E(icaltomessage2),
 	E(imtomessage2),
 	E(essdn_to_username),	
-	E(logon_token)
+	E(logon_token),
+	E(getuserfreebusy),
 };
 #undef E
 #undef EXP
@@ -108,7 +109,7 @@ static constexpr const char *zcore_rpc_names[] = {
 const char *zcore_rpc_idtoname(zcore_callid i)
 {
 	auto j = static_cast<uint8_t>(i);
-	static_assert(std::size(zcore_rpc_names) == static_cast<uint8_t>(zcore_callid::logon_token) + 1);
+	static_assert(std::size(zcore_rpc_names) == static_cast<uint8_t>(zcore_callid::getuserfreebusy) + 1);
 	auto s = j < std::size(zcore_rpc_names) ? zcore_rpc_names[j] : nullptr;
 	return znul(s);
 }
diff --git a/exch/zcore/rpc_ext.cpp b/exch/zcore/rpc_ext.cpp
index 997bd1282..e17f10ad1 100644
--- a/exch/zcore/rpc_ext.cpp
+++ b/exch/zcore/rpc_ext.cpp
@@ -1525,6 +1525,23 @@ static pack_result zrpc_pull(EXT_PULL &x, zcreq_vcftomessage &d)
 	return pack_result::ok;
 }
 
+static pack_result zrpc_pull(EXT_PULL &x, zcreq_getuserfreebusy &d)
+{
+	QRF(x.g_guid(&d.hsession));
+	QRF(x.g_bin(&d.entryid));
+	QRF(x.g_uint64(&d.starttime));
+	QRF(x.g_uint64(&d.endtime));
+	return pack_result::ok;
+}
+
+static pack_result zrpc_push(EXT_PUSH &x, const zcresp_getuserfreebusy &d)
+{
+	QRF(x.p_uint32(d.fb_events.count));
+	for (size_t i = 0; i < d.fb_events.count; ++i)
+		QRF(x.p_fbevent(d.fb_events.fb_events[i]));
+	return pack_result::ok;
+}
+
 static pack_result zrpc_pull(EXT_PULL &x, zcreq_getuseravailability &d)
 {
 	QRF(x.g_guid(&d.hsession));
@@ -1692,6 +1709,7 @@ pack_result rpc_ext_pull_request(const BINARY *pbin_in, zcreq *&prequest)
 	E(imtomessage2)
 	E(essdn_to_username)
 	E(logon_token)
+	E(getuserfreebusy)
 #undef E
 	default:
 		return pack_result::bad_switch;
@@ -1808,6 +1826,7 @@ pack_result rpc_ext_push_response(const zcresp *presponse, BINARY *pbin_out)
 	E(imtomessage2)
 	E(essdn_to_username)
 	E(logon_token)
+	E(getuserfreebusy)
 #undef E
 	default:
 		return pack_result::bad_switch;
diff --git a/exch/zcore/zserver.cpp b/exch/zcore/zserver.cpp
index 722fed009..2e197126a 100644
--- a/exch/zcore/zserver.cpp
+++ b/exch/zcore/zserver.cpp
@@ -22,6 +22,7 @@
 #include <gromox/defs.h>
 #include <gromox/ext_buffer.hpp>
 #include <gromox/fileio.h>
+#include <gromox/freebusy.hpp>
 #include <gromox/int_hash.hpp>
 #include <gromox/mapi_types.hpp>
 #include <gromox/mapidefs.h>
@@ -5080,6 +5081,34 @@ ec_error_t zs_vcftomessage(GUID hsession,
 	return pmessage->write_message(pmsgctnt) ? ecSuccess : ecError;
 }
 
+ec_error_t zs_getuserfreebusy(GUID hsession, BINARY entryid,
+    uint64_t starttime, uint64_t endtime, FB_ARRAY *fb_events)
+{
+	char maildir[256];
+	char username[UADDR_SIZE];
+
+	auto pinfo = zs_query_session(hsession);
+	if (pinfo == nullptr)
+		return ecError;
+	if (!common_util_addressbook_entryid_to_username(entryid,
+	    username, std::size(username)) ||
+	    !system_services_get_maildir(username, maildir, std::size(maildir)))
+		return ecSuccess;
+
+	std::vector<freebusy_event> fb_data;
+	get_freebusy(pinfo->get_username(), maildir, starttime, endtime, fb_data);
+	pinfo.reset();
+
+	fb_events->count = 0;
+	fb_events->fb_events = cu_alloc<freebusy_event>(fb_data.size());
+	for (const auto &fb_event: fb_data) {
+		fb_events->fb_events[fb_events->count++] = fb_event;
+	}
+	fb_data.clear();
+
+	return ecSuccess;
+}
+
 ec_error_t zs_getuseravailability(GUID hsession, BINARY entryid,
     uint64_t starttime, uint64_t endtime, char **ppresult_string)
 {
diff --git a/exch/zcore/zserver.hpp b/exch/zcore/zserver.hpp
index 669795a6d..07b656c42 100644
--- a/exch/zcore/zserver.hpp
+++ b/exch/zcore/zserver.hpp
@@ -137,3 +137,4 @@ extern ec_error_t zs_getuseravailability(GUID ses, BINARY entryid, uint64_t star
 extern ec_error_t zs_setpasswd(const char *username, const char *passwd, const char *new_passwd);
 extern ec_error_t zs_linkmessage(GUID ses, BINARY search_eid, BINARY msg_eid);
 extern ec_error_t zs_essdn_to_username(const char *essdn, char **username);
+extern ec_error_t zs_getuserfreebusy(GUID ses, BINARY entryid, uint64_t starttime, uint64_t endtime, FB_ARRAY *fb_events);
diff --git a/include/gromox/ext_buffer.hpp b/include/gromox/ext_buffer.hpp
index 7affedf10..8be6641d3 100644
--- a/include/gromox/ext_buffer.hpp
+++ b/include/gromox/ext_buffer.hpp
@@ -183,6 +183,8 @@ struct EXT_PULL {
 	pack_result g_apptrecpat(APPOINTMENT_RECUR_PAT *);
 	pack_result g_goid(GLOBALOBJECTID *);
 	pack_result g_msgctnt(MESSAGE_CONTENT *);
+	pack_result g_fb(freebusy_event *);
+	pack_result g_fb_a(FB_ARRAY *);
 
 	template<typename T> inline T *anew() { return static_cast<T *>(m_alloc(sizeof(T))); }
 	template<typename T> inline T *anew(size_t elem) { return static_cast<T *>(m_alloc(sizeof(T) * elem)); }
@@ -275,6 +277,7 @@ struct EXT_PUSH {
 	pack_result p_goid(const GLOBALOBJECTID &);
 	pack_result p_msgctnt(const MESSAGE_CONTENT &);
 	pack_result p_rpchdr(const RPC_HEADER_EXT &);
+	pack_result p_fbevent(const freebusy_event &);
 
 	BOOL b_alloc = false;
 	union {
diff --git a/include/gromox/freebusy.hpp b/include/gromox/freebusy.hpp
new file mode 100644
index 000000000..be6deda66
--- /dev/null
+++ b/include/gromox/freebusy.hpp
@@ -0,0 +1,40 @@
+#pragma once
+#include <vector>
+#include <fmt/core.h>
+#include <fmt/format.h>
+#include <gromox/defs.h>
+#include <gromox/ical.hpp>
+#include <gromox/mapidefs.h>
+#include <gromox/mapi_types.hpp>
+
+using namespace gromox;
+
+template<> struct fmt::formatter<ICAL_TIME>
+{
+	auto parse(format_parse_context &ctx) { return ctx.begin(); }
+	format_context::iterator format(const ICAL_TIME &t, format_context &ctx) const
+	{
+		return fmt::format_to(ctx.out(), "{:04}{:02}{:02}T{:02}{:02}{:02}",
+		       t.year, t.month, t.day, t.hour, t.minute, t.second);
+	}
+};
+
+struct event
+{
+	time_t start_time = 0, end_time = 0;
+	EXCEPTIONINFO *ei = nullptr;
+	EXTENDEDEXCEPTION *xe = nullptr;
+};
+
+struct freebusy_tags
+{
+	freebusy_tags(const char *);
+
+	uint32_t apptstartwhole = 0, apptendwhole = 0, busystatus = 0, recurring = 0,
+		apptrecur = 0, apptsubtype = 0, private_flag = 0, apptstateflags = 0,
+		clipend = 0, location = 0, reminderset = 0, globalobjectid = 0,
+		timezonestruct = 0;
+};
+
+extern GX_EXPORT bool get_freebusy(const char *, const char *, uint64_t, uint64_t,
+	std::vector<freebusy_event> &);
diff --git a/include/gromox/mapidefs.h b/include/gromox/mapidefs.h
index 6e0c50707..dfbfaacb6 100644
--- a/include/gromox/mapidefs.h
+++ b/include/gromox/mapidefs.h
@@ -3,6 +3,7 @@
 #include <cstdint>
 #include <cstring>
 #include <memory>
+#include <optional>
 #include <string>
 #include <gromox/defs.h>
 
@@ -867,6 +868,27 @@ struct DOUBLE_ARRAY {
 	double *mval;
 };
 
+struct freebusy_event_details {
+	freebusy_event_details(char *, char *, char *, bool, bool, bool, bool, bool);
+
+	char *id, *subject, *location;
+	bool is_meeting, is_recurring, is_exception, is_reminderset, is_private;
+};
+
+struct freebusy_event {
+	freebusy_event(time_t, time_t, uint32_t, char *, char *, char *,
+		bool, bool, bool, bool, bool, bool);
+
+	time_t start_time, end_time;
+	uint32_t busy_status;
+	std::optional<freebusy_event_details> details;
+};
+
+struct FB_ARRAY {
+	uint32_t count;
+	freebusy_event *fb_events;
+};
+
 /**
  * The host-endian view of struct GUID is often not needed, and so a plethora
  * of GUIDs exist as bytearrays/FLATUID, mostly when the consumer does not care
diff --git a/include/gromox/zcore_client.hpp b/include/gromox/zcore_client.hpp
index fb36d0c08..284ea70d8 100644
--- a/include/gromox/zcore_client.hpp
+++ b/include/gromox/zcore_client.hpp
@@ -105,5 +105,6 @@ ZCIDL(checksession, (GUID hsession))
 ZCIDL(imtomessage2, (GUID session, uint32_t folder, uint32_t data_type, const char *im_data, IDLOUT LONG_ARRAY *msg_handles))
 ZCIDL(essdn_to_username, (const char *essdn, IDLOUT char **username))
 ZCIDL(logon_token, (const char *token, IDLOUT GUID *hsession))
+ZCIDL(getuserfreebusy, (GUID hsession, BINARY entryid, uint64_t starttime, uint64_t endtime, IDLOUT FB_ARRAY *fb_events))
 #undef ZCIDL
 #undef IDLOUT
diff --git a/include/gromox/zcore_rpc.hpp b/include/gromox/zcore_rpc.hpp
index e62774fbd..c10adc3bc 100644
--- a/include/gromox/zcore_rpc.hpp
+++ b/include/gromox/zcore_rpc.hpp
@@ -100,6 +100,7 @@ enum class zcore_callid : uint8_t {
 	imtomessage2 = 0x58,
 	essdn_to_username = 0x59,
 	logon_token = 0x5a,
+	getuserfreebusy = 0x5b,
 	/* update exch/zcore/names.cpp! */
 };
 
@@ -635,6 +636,13 @@ struct zcreq_essdn_to_username : public zcreq {
 	char *essdn;
 };
 
+struct zcreq_getuserfreebusy : public zcreq {
+	GUID hsession;
+	BINARY entryid;
+	uint64_t starttime;
+	uint64_t endtime;
+};
+
 struct zcresp {
 	zcore_callid call_id;
 	ec_error_t result;
@@ -873,6 +881,10 @@ struct zcresp_essdn_to_username : public zcresp {
 	char *username;
 };
 
+struct zcresp_getuserfreebusy : public zcresp {
+	FB_ARRAY fb_events;
+};
+
 using zcresp_checksession = zcresp;
 using zcresp_configimport = zcresp;
 using zcresp_copyfolder = zcresp;
diff --git a/lib/freebusy.cpp b/lib/freebusy.cpp
new file mode 100644
index 000000000..31b858fb0
--- /dev/null
+++ b/lib/freebusy.cpp
@@ -0,0 +1,487 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// SPDX-FileCopyrightText: 2023 grommunio GmbH
+// This file is part of Gromox.
+#include <vector>
+#include <fmt/core.h>
+#include <fmt/format.h>
+#include <libHX/string.h>
+#include <gromox/defs.h>
+#include <gromox/exmdb_client.hpp>
+#include <gromox/exmdb_rpc.hpp>
+#include <gromox/freebusy.hpp>
+#include <gromox/ical.hpp>
+#include <gromox/mapidefs.h>
+#include <gromox/mapi_types.hpp>
+#include <gromox/rop_util.hpp>
+#include <gromox/scope.hpp>
+#include <gromox/util.hpp>
+
+using namespace gromox;
+namespace exmdb_client = exmdb_client_remote;
+
+freebusy_tags::freebusy_tags(const char *dir)
+{
+	static const PROPERTY_NAME propname_buff[] = {
+		{MNID_ID, PSETID_APPOINTMENT, PidLidAppointmentStartWhole},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidAppointmentEndWhole},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidBusyStatus},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidRecurring},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidAppointmentRecur},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidAppointmentSubType},
+		{MNID_ID, PSETID_COMMON,      PidLidPrivate},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidAppointmentStateFlags},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidClipEnd},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidLocation},
+		{MNID_ID, PSETID_COMMON,      PidLidReminderSet},
+		{MNID_ID, PSETID_MEETING,     PidLidGlobalObjectId},
+		{MNID_ID, PSETID_APPOINTMENT, PidLidTimeZoneStruct},
+	};
+
+	const PROPNAME_ARRAY propnames = {std::size(propname_buff), deconst(propname_buff)};
+	PROPID_ARRAY ids;
+	if (exmdb_client::get_named_propids(dir, false, &propnames, &ids) &&
+	    ids.count == propnames.count) {
+
+		apptstartwhole = PROP_TAG(PT_SYSTIME, ids.ppropid[0]);
+		apptendwhole   = PROP_TAG(PT_SYSTIME, ids.ppropid[1]);
+		busystatus     = PROP_TAG(PT_LONG,    ids.ppropid[2]);
+		recurring      = PROP_TAG(PT_BOOLEAN, ids.ppropid[3]);
+		apptrecur      = PROP_TAG(PT_BINARY,  ids.ppropid[4]);
+		apptsubtype    = PROP_TAG(PT_BOOLEAN, ids.ppropid[5]);
+		private_flag   = PROP_TAG(PT_BOOLEAN, ids.ppropid[6]);
+		apptstateflags = PROP_TAG(PT_LONG,    ids.ppropid[7]);
+		clipend        = PROP_TAG(PT_SYSTIME, ids.ppropid[8]);
+		location       = PROP_TAG(PT_UNICODE, ids.ppropid[9]);
+		reminderset    = PROP_TAG(PT_BOOLEAN, ids.ppropid[10]);
+		globalobjectid = PROP_TAG(PT_BINARY,  ids.ppropid[11]);
+		timezonestruct = PROP_TAG(PT_BINARY,  ids.ppropid[12]);
+	}
+}
+
+freebusy_event_details::freebusy_event_details(char *ev_id, char *ev_subject,
+	char *ev_location, bool ev_meeting, bool ev_recurring, bool ev_exception,
+	bool ev_reminderset, bool ev_private) :
+		id(ev_id), subject(ev_subject), location(ev_location),
+		is_meeting(ev_meeting), is_recurring(ev_recurring),
+		is_exception(ev_exception), is_reminderset(ev_reminderset),
+		is_private(ev_private) {}
+
+freebusy_event::freebusy_event(time_t start, time_t end, uint32_t b_status,
+	char *ev_id, char *ev_subject, char *ev_location,
+	bool ev_meeting, bool ev_recurring, bool ev_exception, bool ev_reminderset,
+	bool ev_private, bool detailed) :
+		start_time(start), end_time(end), busy_status(b_status)
+{
+	if (!detailed)
+		return;
+
+	details = std::make_optional(freebusy_event_details{ev_id, ev_subject,
+		ev_location, ev_meeting, ev_recurring, ev_exception, ev_reminderset, ev_private});
+}
+
+static bool fill_tzcom(ical_component &tzcom, const SYSTEMTIME &sys, int year,
+    int from_bias, int to_bias, bool dstmonth)
+{
+	std::string str;
+	if (!dstmonth) {
+		str = "16010101T000000";
+	} else if (sys.year == 0) {
+		int day = ical_get_dayofmonth(year, sys.month, sys.day,	sys.dayofweek);
+		str = fmt::format("{}", ICAL_TIME{year, sys.month, day,
+		      sys.hour, sys.minute, sys.second});
+	} else if (sys.year == 1) {
+		str = fmt::format("{}", ICAL_TIME{year, sys.month, sys.day,
+		      sys.hour, sys.minute, sys.second});
+	} else {
+		return false;
+	}
+
+	int utc_offset = -from_bias;
+	tzcom.append_line("TZOFFSETFROM", fmt::format("{:+03}{:02}",
+		utc_offset / 60, abs(utc_offset) % 60));
+	utc_offset = -to_bias;
+	tzcom.append_line("TZOFFSETTO", fmt::format("{:+03}{:02}",
+		utc_offset / 60, abs(utc_offset) % 60));
+	tzcom.append_line("DTSTART", std::move(str));
+
+	if (!dstmonth)
+		return true;
+	if (sys.year == 0) {
+		auto &line = tzcom.append_line("RRULE");
+		line.append_value("FREQ", "YEARLY");
+		int order = sys.day == 5 ? -1 : sys.day;
+		auto dow = weekday_to_str(sys.dayofweek);
+		if (dow == nullptr)
+			return false;
+		line.append_value("BYDAY", fmt::format("{}{}", order, dow));
+		line.append_value("BYMONTH", fmt::format("{}", sys.month));
+	} else if (sys.year == 1) {
+		auto &line = tzcom.append_line("RRULE");
+		line.append_value("FREQ", "YEARLY");
+		line.append_value("BYMONTHDAY", fmt::format("{}", sys.day));
+		line.append_value("BYMONTH", fmt::format("{}", sys.month));
+	}
+	return true;
+}
+
+static std::optional<ical_component> tz_to_vtimezone(int year,
+    const char *tzid, const TIMEZONESTRUCT &tz)
+{
+	std::optional<ical_component> com("VTIMEZONE");
+	com->append_line("TZID", tzid);
+
+	auto &stdtime = com->append_comp("STANDARD");
+	int std_bias  = tz.bias + tz.standardbias;
+	int dst_bias  = tz.bias + tz.daylightbias;
+	if (!fill_tzcom(stdtime, tz.standarddate, year, dst_bias, std_bias,
+	    tz.daylightdate.month))
+		return std::nullopt;
+	if (tz.daylightdate.month == 0)
+		return com;
+	auto &dsttime = com->append_comp("DAYLIGHT");
+	if (!fill_tzcom(dsttime, tz.daylightdate, year, std_bias, dst_bias,
+	    tz.standarddate.month))
+		return std::nullopt;
+	return com;
+}
+
+static bool recurrencepattern_to_rrule(const ical_component *tzcom,
+    time_t start_whole, const APPOINTMENT_RECUR_PAT &apr, ICAL_RRULE *irrule)
+{
+	auto &rpat = apr.recur_pat;
+	ICAL_TIME itime;
+	ical_line line("RRULE");
+
+	switch (rpat.patterntype) {
+	case PATTERNTYPE_DAY:
+		line.append_value("FREQ", "DAILY");
+		line.append_value("INTERVAL", fmt::format("{}", rpat.period / 1440));
+		break;
+	case PATTERNTYPE_WEEK: {
+		line.append_value("FREQ", "WEEKLY");
+		line.append_value("INTERVAL", fmt::format("{}", rpat.period));
+		auto &val = line.append_value("BYDAY");
+		for (unsigned int wd = 0; wd < 7; ++wd)
+			if (rpat.pts.weekrecur & (1 << wd))
+				val.append_subval(weekday_to_str(wd));
+		break;
+	}
+	case PATTERNTYPE_MONTH:
+	case PATTERNTYPE_HJMONTH: {
+		auto monthly  = rpat.period % 12 != 0;
+		auto interval = rpat.period;
+		line.append_value("FREQ", monthly ? "MONTHLY" : "YEARLY");
+		if (monthly)
+			interval /= 12;
+		line.append_value("INTERVAL", fmt::format("{}", interval));
+		line.append_value("BYMONTHDAY", fmt::format("{}",
+			rpat.pts.dayofmonth == 31 ? -1 : rpat.pts.dayofmonth));//test what happens if making recurrence with day30/31 (rather than lastday)
+		if (monthly)
+			break;
+		ical_get_itime_from_yearday(1601, rpat.firstdatetime / 1440 + 1, &itime);
+		line.append_value("BYMONTH", fmt::format("{}", itime.month));
+		break;
+	}
+	case PATTERNTYPE_MONTHNTH:
+	case PATTERNTYPE_HJMONTHNTH: {
+		auto monthly  = rpat.period % 12 != 0;
+		auto interval = rpat.period;
+		line.append_value("FREQ", monthly ? "MONTHLY" : "YEARLY");
+		if (monthly)
+			interval /= 12;
+		line.append_value("INTERVAL", fmt::format("{}", interval));
+		auto &pts = rpat.pts;
+		auto &val = line.append_value("BYDAY");
+		for (unsigned int wd = 0; wd < 7; ++wd)
+			if (pts.monthnth.weekrecur & (1 << wd))
+				val.append_subval(weekday_to_str(wd));
+		line.append_value("BYSETPOS", fmt::format("{}",
+			pts.monthnth.recurnum == 5 ? -1 : pts.monthnth.recurnum));
+		if (monthly)
+			break;
+		line.append_value("BYMONTH", fmt::format("{}", rpat.firstdatetime));
+		break;
+	}
+	default:
+		return false;
+	}
+	if (rpat.endtype == ENDTYPE_AFTER_N_OCCURRENCES) {
+		line.append_value("COUNT", fmt::format("{}", rpat.occurrencecount));
+	} else if (rpat.endtype == ENDTYPE_AFTER_DATE) {
+		auto ut = rop_util_rtime_to_unix(rpat.enddate + apr.starttimeoffset);
+		ical_utc_to_datetime(tzcom, ut, &itime);
+		line.append_value("UNTIL", fmt::format("{}Z", itime));
+	}
+	if (rpat.patterntype == PATTERNTYPE_WEEK) {
+		auto wd = weekday_to_str(rpat.firstdow);
+		if (wd == nullptr)
+			return false;
+		line.append_value("WKST", wd);
+	}
+	return ical_parse_rrule(tzcom, start_whole, &line.value_list, irrule);
+}
+
+static bool find_recur_times(const ical_component *tzcom,
+    time_t start_whole, const APPOINTMENT_RECUR_PAT &apr,
+    time_t start_time, time_t end_time, std::vector<event> &evlist)
+{
+	ICAL_RRULE irrule;
+
+	if (!recurrencepattern_to_rrule(tzcom, start_whole, apr, &irrule))
+		return false;
+	do {
+		auto itime = irrule.instance_itime;
+		time_t ut{}, utnz{};
+		if (!ical_itime_to_utc(tzcom, itime, &ut))
+			break;
+		if (ut < start_time)
+			continue;
+		if (!ical_itime_to_utc(nullptr, itime, &utnz))
+			break;
+		auto &ei = apr.pexceptioninfo;
+		auto time_test = [&](const EXCEPTIONINFO &e) {
+			return rop_util_rtime_to_unix(e.originalstartdate) == utnz;
+		};
+		if (std::any_of(&ei[0], &ei[apr.exceptioncount], time_test))
+			continue;
+		evlist.push_back(event{ut, ut + (apr.endtimeoffset - apr.starttimeoffset) * 60});
+		if (ut >= end_time)
+			break;
+	} while (irrule.iterate());
+	for (unsigned int i = 0; i < apr.exceptioncount; ++i) {
+		auto ut = rop_util_rtime_to_unix(apr.pexceptioninfo[i].startdatetime);
+		ICAL_TIME itime;
+		if (!ical_utc_to_datetime(nullptr, ut, &itime) ||
+		    !ical_itime_to_utc(tzcom, itime, &ut) ||
+		    ut < start_time || ut > end_time)
+			continue;
+		event event = {ut};
+		ut = rop_util_rtime_to_unix(apr.pexceptioninfo[i].enddatetime);
+		if (!ical_utc_to_datetime(nullptr, ut, &itime) ||
+		    !ical_itime_to_utc(tzcom, itime, &ut))
+			continue;
+		event.end_time = ut;
+		event.ei = &apr.pexceptioninfo[i];
+		event.xe = &apr.pextendedexception[i];
+		evlist.push_back(std::move(event));
+	}
+	return true;
+}
+
+static int goid_to_icaluid2(BINARY *gobj, std::string &uid_buf)
+{
+	EXT_PUSH ext_push;
+	char guidbuf[16], ngidbuf[56];
+	GLOBALOBJECTID ngid;
+
+	if (gobj == nullptr) {
+		if (!ext_push.init(guidbuf, std::size(guidbuf), 0) ||
+		    ext_push.p_guid(GUID::random_new()) != EXT_ERR_SUCCESS)
+			return -EIO;
+		ngid.arrayid = EncodedGlobalId;
+		ngid.creationtime = rop_util_unix_to_nttime(time(nullptr));
+		ngid.data.cb = 16;
+		ngid.data.pc = guidbuf;
+		uid_buf.resize(std::size(ngidbuf) * 2 + 1);
+		if (!ext_push.init(ngidbuf, std::size(ngidbuf), 0) ||
+		    ext_push.p_goid(ngid) != EXT_ERR_SUCCESS ||
+		    !encode_hex_binary(ngidbuf, ext_push.m_offset,
+		    uid_buf.data(), uid_buf.size()))
+			return -EIO;
+		return 2;
+	}
+
+	EXT_PULL ext_pull;
+	auto cl_0 = make_scope_exit([&]() { free(ngid.data.pc); });
+	ext_pull.init(gobj->pb, gobj->cb, malloc, 0);
+	if (ext_pull.g_goid(&ngid) != EXT_ERR_SUCCESS)
+		return -EIO;
+	static_assert(sizeof(ThirdPartyGlobalId) == 12);
+	if (ngid.data.cb >= 12 && memcmp(ngid.data.pc, ThirdPartyGlobalId, 12) == 0) {
+		auto m = ngid.data.cb - 12;
+		if (m > 255)
+			m = 255;//check if this is the typical boundary(OXFB)
+		uid_buf.assign(&ngid.data.pc[12], m);
+		return 1;
+	}
+
+	uid_buf.resize(56*2+1);
+	ngid.year = ngid.month = ngid.day = 0;
+	if (!ext_push.init(ngidbuf, std::size(ngidbuf), 0) ||
+	    ext_push.p_goid(ngid) != EXT_ERR_SUCCESS ||
+	    !encode_hex_binary(ngidbuf, ext_push.m_offset, uid_buf.data(), uid_buf.size()))
+		return -EIO;
+	return 2;
+}
+
+static bool goid_to_icaluid(BINARY *gobj, std::string &uid_buf)
+{
+	auto ret = goid_to_icaluid2(gobj, uid_buf);
+	if (ret < 0)
+		return false;
+	if (ret == 2)
+		HX_strupper(uid_buf.data());
+	return true;
+}
+
+bool get_freebusy(const char *username, const char *dir,
+	uint64_t start_time, uint64_t end_time, std::vector<freebusy_event>& fb_data)
+{
+	uint32_t permission = 0;
+	auto cal_eid = rop_util_make_eid_ex(1, PRIVATE_FID_CALENDAR);
+
+	if (username != nullptr) {
+		if (!exmdb_client::get_folder_perm(dir, cal_eid, username, &permission))
+			return false;
+		if (!(permission & (frightsFreeBusySimple | frightsFreeBusyDetailed | frightsReadAny)))
+			return false;
+	} else {
+		permission = frightsFreeBusyDetailed | frightsReadAny;
+	}
+
+	freebusy_tags ptag(dir);
+	auto start_nttime = rop_util_unix_to_nttime(start_time);
+	auto end_nttime   = rop_util_unix_to_nttime(end_time);
+	bool detailed     = permission & (frightsFreeBusyDetailed | frightsReadAny);
+	static constexpr uint8_t fixed_true = 1;
+
+	/* C1: apptstartwhole >= start && apptstartwhole <= end */
+	RESTRICTION_PROPERTY rst_1 = {RELOP_GE, ptag.apptstartwhole, {ptag.apptstartwhole, &start_nttime}};
+	RESTRICTION_PROPERTY rst_2 = {RELOP_LE, ptag.apptstartwhole, {ptag.apptstartwhole, &end_nttime}};
+	RESTRICTION rst_3[2]       = {{RES_PROPERTY, {&rst_1}}, {RES_PROPERTY, {&rst_2}}};
+	RESTRICTION_AND_OR rst_4   = {std::size(rst_3), rst_3};
+
+	/* C2: apptendwhole >= start && apptendwhole <= end */
+	RESTRICTION_PROPERTY rst_5 = {RELOP_GE, ptag.apptendwhole, {ptag.apptendwhole, &start_nttime}};
+	RESTRICTION_PROPERTY rst_6 = {RELOP_LE, ptag.apptendwhole, {ptag.apptendwhole, &end_nttime}};
+	RESTRICTION rst_7[2]       = {{RES_PROPERTY, {&rst_5}}, {RES_PROPERTY, {&rst_6}}};
+	RESTRICTION_AND_OR rst_8   = {std::size(rst_7), rst_7};
+
+	/* C3: apptstartwhole < start && apptendwhole > end */
+	RESTRICTION_PROPERTY rst_9  = {RELOP_LT, ptag.apptstartwhole, {ptag.apptstartwhole, &start_nttime}};
+	RESTRICTION_PROPERTY rst_10 = {RELOP_GT, ptag.apptendwhole, {ptag.apptendwhole, &end_nttime}};
+	RESTRICTION rst_11[2]       = {{RES_PROPERTY, {&rst_9}}, {RES_PROPERTY, {&rst_10}}};
+	RESTRICTION_AND_OR rst_12   = {std::size(rst_11), rst_11};
+
+	/* C4: have(clipend) && recurring && clipend >= start */
+	RESTRICTION_EXIST rst_13    = {ptag.clipend};
+	RESTRICTION_PROPERTY rst_14 = {RELOP_EQ, ptag.recurring, {ptag.recurring, deconst(&fixed_true)}};
+	RESTRICTION_PROPERTY rst_15 = {RELOP_GE, ptag.clipend, {ptag.clipend, &start_nttime}};
+	RESTRICTION rst_16[3]       = {{RES_EXIST, {&rst_13}}, {RES_PROPERTY, {&rst_14}}, {RES_PROPERTY, {&rst_15}}};
+	RESTRICTION_AND_OR rst_17   = {std::size(rst_16), rst_16};
+
+	/* C5: !have(clipend) && recurring && apptstartwhole <= end */
+	RESTRICTION_EXIST rst_18    = {ptag.clipend};
+	RESTRICTION rst_19          = {RES_EXIST, {&rst_18}};
+	RESTRICTION_PROPERTY rst_20 = {RELOP_EQ, ptag.recurring, {ptag.recurring, deconst(&fixed_true)}};
+	RESTRICTION_PROPERTY rst_21 = {RELOP_LE, ptag.apptstartwhole, {ptag.apptstartwhole, &end_nttime}};
+	RESTRICTION rst_22[3]       = {{RES_NOT, {&rst_19}}, {RES_PROPERTY, {&rst_20}}, {RES_PROPERTY, {&rst_21}}};
+	RESTRICTION_AND_OR rst_23   = {std::size(rst_22), rst_22};
+
+	/* OR over C1-C5 */
+	RESTRICTION rst_24[5]       = {{RES_AND, {&rst_4}}, {RES_AND, {&rst_8}}, {RES_AND, {&rst_12}}, {RES_AND, {&rst_17}}, {RES_AND, {&rst_23}}};
+	RESTRICTION_AND_OR rst_25   = {std::size(rst_24), rst_24};
+	RESTRICTION rst_26          = {RES_OR, {&rst_25}};
+
+	uint32_t table_id = 0, row_count = 0;
+	if (!exmdb_client::load_content_table(dir, CP_ACP, cal_eid, nullptr,
+	    TABLE_FLAG_NONOTIFICATIONS, &rst_26, nullptr, &table_id, &row_count))
+		return false;
+
+	auto cl_0 = make_scope_exit([&]() { exmdb_client::unload_table(dir, table_id);});
+
+	uint32_t proptag_buff[] = {
+		ptag.apptstartwhole, ptag.apptendwhole, ptag.busystatus,
+		ptag.recurring, ptag.apptrecur, ptag.apptsubtype, ptag.private_flag,
+		ptag.apptstateflags, ptag.location, ptag.reminderset,
+		ptag.globalobjectid, ptag.timezonestruct, PR_SUBJECT,
+	};
+	const PROPTAG_ARRAY proptags = {std::size(proptag_buff), deconst(proptag_buff)};
+	TARRAY_SET rows;
+	if (!exmdb_client::query_table(dir, nullptr, CP_ACP, table_id,
+	    &proptags, 0, row_count, &rows))
+		return false;
+
+	for (size_t i = 0; i < rows.count; ++i) {
+		std::string uid_buf;
+		if (!goid_to_icaluid(rows.pparray[i]->get<BINARY>(ptag.globalobjectid), uid_buf))
+			continue;
+		auto ts = rows.pparray[i]->get<const uint64_t>(ptag.apptstartwhole);
+		if (ts == nullptr)
+			continue;
+		auto start_whole = rop_util_nttime_to_unix(*ts);
+		ts = rows.pparray[i]->get<uint64_t>(ptag.apptendwhole);
+		if (ts == nullptr)
+			continue;
+		auto end_whole   = rop_util_nttime_to_unix(*ts);
+		auto subject     = rows.pparray[i]->get<char>(PR_SUBJECT);
+		auto location    = rows.pparray[i]->get<char>(ptag.location);
+		auto flag        = rows.pparray[i]->get<const uint8_t>(ptag.reminderset);
+		bool is_reminder = flag != nullptr && *flag != 0;
+		flag = rows.pparray[i]->get<uint8_t>(ptag.private_flag);
+		bool is_private  = flag != nullptr && *flag != 0;
+		auto num = rows.pparray[i]->get<const uint32_t>(ptag.busystatus);
+		uint32_t busy_type = num == nullptr || *num > olWorkingElsewhere ? 0 : *num;
+		num = rows.pparray[i]->get<uint32_t>(ptag.apptstateflags);
+		bool is_meeting = num != nullptr && *num & asfMeeting;
+		flag = rows.pparray[i]->get<uint8_t>(ptag.recurring);
+
+		// non-recurring appointments
+		if (flag == nullptr || *flag == 0) {
+			fb_data.emplace_back(start_whole, end_whole, busy_type, uid_buf.data(),
+				subject, location, is_meeting, false, false, is_reminder, is_private, detailed);
+			continue;
+		}
+		// recurring appointments
+		EXT_PULL ext_pull;
+		std::optional<ical_component> tzcom;
+		auto bin = rows.pparray[i]->get<BINARY>(ptag.timezonestruct);
+		if (bin != nullptr) {
+			TIMEZONESTRUCT tz;
+			ext_pull.init(bin->pb, bin->cb, exmdb_rpc_alloc, EXT_FLAG_UTF16);
+			if (ext_pull.g_tzstruct(&tz) != EXT_ERR_SUCCESS)
+				continue;
+			tzcom = tz_to_vtimezone(1600, "timezone", tz);
+			if (!tzcom.has_value())
+				continue;
+		}
+
+		bin = rows.pparray[i]->get<BINARY>(ptag.apptrecur);
+		if (bin == nullptr)
+			continue;
+		APPOINTMENT_RECUR_PAT apprecurr;
+		ext_pull.init(bin->pb, bin->cb, exmdb_rpc_alloc, EXT_FLAG_UTF16);
+		if (ext_pull.g_apptrecpat(&apprecurr) != EXT_ERR_SUCCESS)
+			continue;
+
+		std::vector<event> event_list;
+		if (!find_recur_times(tzcom.has_value() ? &*tzcom : nullptr,
+		    start_whole, apprecurr, start_time, end_time, event_list))
+			continue;
+
+		for (const auto &event : event_list) {
+			if (event.ei == nullptr || event.xe == nullptr) {
+				fb_data.emplace_back(event.start_time, event.end_time, busy_type,
+					uid_buf.data(), subject, location, is_meeting, TRUE, false,
+					is_reminder, is_private, detailed);
+				continue;
+			}
+
+			bool ov_meeting  = (event.ei->overrideflags & ARO_MEETINGTYPE) ? event.ei->meetingtype & 1 : is_meeting;
+			bool ov_reminder = (event.ei->overrideflags & ARO_REMINDER)    ? event.ei->reminderset == 0 : is_reminder;
+			uint32_t ov_busy = (event.ei->overrideflags & ARO_BUSYSTATUS)  ? event.ei->busystatus : busy_type;
+			auto ov_subj     = (event.ei->overrideflags & ARO_SUBJECT)     ? event.xe->subject : subject;
+			auto ov_location = (event.ei->overrideflags & ARO_LOCATION)    ? event.xe->location : location;
+
+			fb_data.emplace_back(event.start_time, event.end_time, ov_busy,
+				uid_buf.data(), ov_subj, ov_location, ov_meeting, TRUE, TRUE,
+				ov_reminder, is_private, detailed);
+		}
+	}
+
+	cl_0.release();
+	if (!exmdb_client::unload_table(dir, table_id))
+		return false;
+
+	return true;
+}
\ No newline at end of file
diff --git a/lib/mapi/ext_buffer.cpp b/lib/mapi/ext_buffer.cpp
index d399727a5..6d0fead1b 100644
--- a/lib/mapi/ext_buffer.cpp
+++ b/lib/mapi/ext_buffer.cpp
@@ -2045,6 +2045,48 @@ pack_result EXT_PULL::g_msgctnt(MESSAGE_CONTENT *r)
 	return EXT_ERR_SUCCESS;
 }
 
+pack_result EXT_PULL::g_fb(freebusy_event *fb_event)
+{
+	TRY(g_int64(&fb_event->start_time));
+	TRY(g_int64(&fb_event->end_time));
+	TRY(g_uint32(&fb_event->busy_status));
+	BOOL b;
+	TRY(g_bool(&b));
+
+	if (b) {
+		TRY(g_str(&fb_event->details->id));
+		TRY(g_str(&fb_event->details->subject));
+		TRY(g_bool(&b));
+		if (b)
+			TRY(g_str(&fb_event->details->location));
+		TRY(g_bool(&b)); fb_event->details->is_meeting     = b;
+		TRY(g_bool(&b)); fb_event->details->is_recurring   = b;
+		TRY(g_bool(&b)); fb_event->details->is_exception   = b;
+		TRY(g_bool(&b)); fb_event->details->is_reminderset = b;
+		TRY(g_bool(&b)); fb_event->details->is_private     = b;
+	}
+
+	return EXT_ERR_SUCCESS;
+}
+
+pack_result EXT_PULL::g_fb_a(FB_ARRAY *r)
+{
+	TRY(g_uint32(&r->count));
+	if (r->count == 0) {
+		r->fb_events = NULL;
+		return EXT_ERR_SUCCESS;
+	}
+	r->fb_events = anew<freebusy_event>(r->count);
+	if (r->fb_events == nullptr) {
+		r->count = 0;
+		return EXT_ERR_ALLOC;
+	}
+
+	for (size_t i = 0; i < r->count; ++i)
+		TRY(g_fb(&r->fb_events[i]));
+	return EXT_ERR_SUCCESS;
+}
+
 BOOL EXT_PUSH::init(void *pdata, uint32_t alloc_size,
     uint32_t flags, const EXT_BUFFER_MGT *mgt)
 {
@@ -3432,6 +3474,27 @@ pack_result EXT_PUSH::p_msgctnt(const MESSAGE_CONTENT &r)
 	}
 }
 
+pack_result EXT_PUSH::p_fbevent(const freebusy_event &r)
+{
+	TRY(p_int64(r.start_time));
+	TRY(p_int64(r.end_time));
+	TRY(p_uint32(r.busy_status));
+	TRY(p_bool(r.details.has_value()));
+	if (r.details.has_value()) {
+		TRY(p_str(r.details->id));
+		TRY(p_str(r.details->subject));
+		TRY(p_bool(r.details->location != nullptr));
+		if (r.details->location != nullptr)
+			TRY(p_str(r.details->location));
+		TRY(p_bool(r.details->is_meeting));
+		TRY(p_bool(r.details->is_recurring));
+		TRY(p_bool(r.details->is_exception));
+		TRY(p_bool(r.details->is_reminderset));
+		TRY(p_bool(r.details->is_private));
+	}
+	return pack_result::ok;
+}
+
 uint8_t *EXT_PUSH::release()
 {
 	auto p = this;
diff --git a/php_mapi/mapi.cpp b/php_mapi/mapi.cpp
index a40b2c0a7..5a301e7f2 100644
--- a/php_mapi/mapi.cpp
+++ b/php_mapi/mapi.cpp
@@ -3209,6 +3209,51 @@ static ZEND_FUNCTION(mapi_zarafa_setpermissionrules)
 	RETVAL_TRUE;
 }
 
+/*
+	This function will get user's freebusy data
+
+	param session[in]	session object
+	param entryid[in]	user's entryid
+	param starttime		unix time stamp
+	param endtime 		unix time stamp
+	return		Array of user's freebusy data,
+						Array of events, empty array means not
+						found. fields:
+						starttime, endtime, busytype, id, subject, location,
+						rest are all bool(absence means false). meeting, recurring,
+						exception, reminderset, private
+*/
+static ZEND_FUNCTION(mapi_getuserfreebusy)
+{
+	ZCL_MEMORY;
+	zend_long starttime, endtime;
+	BINARY entryid;
+	size_t eid_size = 0;
+	zval pzfbevents, *pzresource;
+	FB_ARRAY fb_events;
+	MAPI_RESOURCE *psession;
+
+	ZVAL_NULL(&pzfbevents);
+	if (zend_parse_parameters(ZEND_NUM_ARGS(), "rsll",
+	    &pzresource, &entryid.pb, &eid_size, &starttime, &endtime) == FAILURE ||
+	    pzresource == nullptr || entryid.pb == nullptr || eid_size == 0)
+		pthrow(ecInvalidParam);
+	entryid.cb = eid_size;
+	ZEND_FETCH_RESOURCE(psession, MAPI_RESOURCE*,
+		&pzresource, -1, name_mapi_session, le_mapi_session);
+	if (psession->type != zs_objtype::session)
+		pthrow(ecInvalidObject);
+	auto result = zclient_getuserfreebusy(psession->hsession, entryid, starttime,
+		endtime, &fb_events);
+	if (result != ecSuccess)
+		pthrow(result);
+	if (auto err = fb_array_to_php(&fb_events, &pzfbevents); err != ecSuccess)
+		pthrow(err);
+	zarray_init(return_value);
+	add_assoc_zval(return_value, "fbevents", &pzfbevents);
+	MAPI_G(hr) = ecSuccess;
+}
+
 /*
 	This function will get user's freebusy data
 	
@@ -4477,6 +4522,7 @@ static zend_function_entry mapi_functions[] = {
 	F(mapi_decompressrtf)
 	F(mapi_zarafa_getpermissionrules)
 	F(mapi_zarafa_setpermissionrules)
+	F(mapi_getuserfreebusy)
 	F(mapi_getuseravailability)
 	F(mapi_exportchanges_config)
 	F(mapi_exportchanges_synchronize)
diff --git a/php_mapi/mapi.stub.php b/php_mapi/mapi.stub.php
index da75a29f5..7ee25f310 100644
--- a/php_mapi/mapi.stub.php
+++ b/php_mapi/mapi.stub.php
@@ -81,6 +81,7 @@ function mapi_getidsfromnames(resource $store, array $names, ?array $guids = nul
 function mapi_decompressrtf(string $data) : string|false {}
 function mapi_zarafa_getpermissionrules(resource $any, int $type) : array|false {}
 function mapi_zarafa_setpermissionrules(resource $any, array $perms) : bool {}
+function mapi_getuserfreebusy(resource $ses, string $entryid, int $start, int $end) : array|false {}
 function mapi_getuseravailability(resource $ses, string $entryid, int $start, int $end) : string|false {}
 function mapi_exportchanges_config(resource $e, resource $stream, int $flags, mixed $i, mixed $restrict, mixed $inclprop, mixed $exclprop, int $bufsize) : bool {}
 function mapi_exportchanges_synchronize(resource $x) : mixed {}
diff --git a/php_mapi/mapi_arginfo.hpp b/php_mapi/mapi_arginfo.hpp
index c934c75a5..f401f3358 100644
--- a/php_mapi/mapi_arginfo.hpp
+++ b/php_mapi/mapi_arginfo.hpp
@@ -416,6 +416,13 @@ ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_mapi_zarafa_setpermissionrules,
 	ZEND_ARG_TYPE_INFO(0, perms, IS_ARRAY, 0)
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_mapi_getuserfreebusy, 0, 4, MAY_BE_ARRAY|MAY_BE_FALSE)
+	ZEND_ARG_OBJ_INFO(0, ses, resource, 0)
+	ZEND_ARG_TYPE_INFO(0, entryid, IS_STRING, 0)
+	ZEND_ARG_TYPE_INFO(0, start, IS_LONG, 0)
+	ZEND_ARG_TYPE_INFO(0, end, IS_LONG, 0)
+ZEND_END_ARG_INFO()
+
 ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_mapi_getuseravailability, 0, 4, MAY_BE_STRING|MAY_BE_FALSE)
 	ZEND_ARG_OBJ_INFO(0, ses, resource, 0)
 	ZEND_ARG_TYPE_INFO(0, entryid, IS_STRING, 0)
diff --git a/php_mapi/rpc_ext.cpp b/php_mapi/rpc_ext.cpp
index 5bbe698ca..2d7a1a3eb 100644
--- a/php_mapi/rpc_ext.cpp
+++ b/php_mapi/rpc_ext.cpp
@@ -1064,6 +1064,21 @@ static pack_result zrpc_push(PUSH_CTX &x, const zcreq_vcftomessage &d)
 	return pack_result::ok;
 }
 
+static pack_result zrpc_push(PUSH_CTX &x, const zcreq_getuserfreebusy &d)
+{
+	TRY(x.p_guid(d.hsession));
+	TRY(x.p_bin(d.entryid));
+	TRY(x.p_uint64(d.starttime));
+	TRY(x.p_uint64(d.endtime));
+	return pack_result::ok;
+}
+
+static pack_result zrpc_pull(PULL_CTX &x, zcresp_getuserfreebusy &d)
+{
+	TRY(x.g_fb_a(&d.fb_events));
+	return pack_result::ok;
+}
+
 static pack_result zrpc_push(PUSH_CTX &x, const zcreq_getuseravailability &d)
 {
 	TRY(x.p_guid(d.hsession));
@@ -1212,6 +1227,7 @@ pack_result rpc_ext_push_request(const zcreq *prequest, BINARY *pbin_out)
 	E(imtomessage2)
 	E(essdn_to_username)
 	E(logon_token)
+	E(getuserfreebusy)
 #undef E
 	default:
 		return pack_result::bad_switch;
@@ -1325,6 +1341,7 @@ pack_result rpc_ext_pull_response(const BINARY *pbin_in, zcresp *presponse)
 	E(imtomessage2)
 	E(essdn_to_username)
 	E(logon_token)
+	E(getuserfreebusy)
 #undef E
 	default:
 		return pack_result::bad_switch;
diff --git a/php_mapi/type_conversion.cpp b/php_mapi/type_conversion.cpp
index 016b27159..179c1fb82 100644
--- a/php_mapi/type_conversion.cpp
+++ b/php_mapi/type_conversion.cpp
@@ -103,6 +103,31 @@ ec_error_t binary_array_to_php(const BINARY_ARRAY *pbins, zval *pzval)
 	return ecSuccess;
 }
 
+ec_error_t fb_array_to_php(const FB_ARRAY *pfbs, zval *pzval)
+{
+	zval pzvalfbevent;
+	zarray_init(pzval);
+	for (size_t i = 0; i < pfbs->count; ++i) {
+		zarray_init(&pzvalfbevent);
+		add_assoc_long(&pzvalfbevent, "start", pfbs->fb_events[i].start_time);
+		add_assoc_long(&pzvalfbevent, "end", pfbs->fb_events[i].end_time);
+		add_assoc_long(&pzvalfbevent, "busystatus", pfbs->fb_events[i].busy_status);
+		if (pfbs->fb_events[i].details->id != nullptr)
+			add_assoc_string(&pzvalfbevent, "id", pfbs->fb_events[i].details->id);
+		if (pfbs->fb_events[i].details->subject != nullptr)
+			add_assoc_string(&pzvalfbevent, "subject", pfbs->fb_events[i].details->subject);
+		if (pfbs->fb_events[i].details->location != nullptr)
+			add_assoc_string(&pzvalfbevent, "location", pfbs->fb_events[i].details->location);
+		add_assoc_bool(&pzvalfbevent, "meeting", pfbs->fb_events[i].details->is_meeting);
+		add_assoc_bool(&pzvalfbevent, "recurring", pfbs->fb_events[i].details->is_recurring);
+		add_assoc_bool(&pzvalfbevent, "exception", pfbs->fb_events[i].details->is_exception);
+		add_assoc_bool(&pzvalfbevent, "reminderset", pfbs->fb_events[i].details->is_reminderset);
+		add_assoc_bool(&pzvalfbevent, "private", pfbs->fb_events[i].details->is_private);
+		add_next_index_zval(pzval, &pzvalfbevent);
+	}
+	return ecSuccess;
+}
+
 ec_error_t php_to_sortorder_set(zval *pzval, SORTORDER_SET *pset)
 {
 	unsigned long idx;
@@ -300,7 +325,7 @@ static void *php_to_propval(zval *entry, uint16_t proptype)
 			return NULL;
 		}
 		ZEND_HASH_FOREACH_VAL(pdata_hash, data_entry) {
-			xs->ps[j++] = zval_get_long(data_entry);
+			xs->ps[j++] = zval_get_long(entry);
 		} ZEND_HASH_FOREACH_END();
 		break;
 	}
@@ -324,7 +349,7 @@ static void *php_to_propval(zval *entry, uint16_t proptype)
 			return NULL;
 		}
 		ZEND_HASH_FOREACH_VAL(pdata_hash, data_entry) {
-			xl->pl[j++] = zval_get_long(data_entry);
+			xl->pl[j++] = zval_get_long(entry);
 		} ZEND_HASH_FOREACH_END();
 		break;
 	}
diff --git a/php_mapi/type_conversion.hpp b/php_mapi/type_conversion.hpp
index 1a30f0f6d..4579ebca2 100644
--- a/php_mapi/type_conversion.hpp
+++ b/php_mapi/type_conversion.hpp
@@ -27,6 +27,7 @@ extern ec_error_t state_array_to_php(const STATE_ARRAY *, zval *);
 extern ec_error_t php_to_state_array(zval *, STATE_ARRAY *);
 extern ec_error_t znotification_array_to_php(ZNOTIFICATION_ARRAY *, zval *);
 extern ec_error_t php_to_propname_array(zval *names, zval *guids, PROPNAME_ARRAY *);
+extern ec_error_t fb_array_to_php(const FB_ARRAY *, zval *);
 
 /* Wrap this so cov-scan only complains once (hopefully) */
 static inline void zarray_init(zval *x)