diff --git a/.tool-versions b/.tool-versions
index 0b827a9..532f92b 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,2 +1,2 @@
-elixir 1.12.1-otp-24
-erlang 24.0.2
+elixir 1.14.5-otp-25
+erlang 25.3.2
diff --git a/lib/cocktail/builder/i_calendar.ex b/lib/cocktail/builder/i_calendar.ex
index 35cf3be..41189bf 100644
--- a/lib/cocktail/builder/i_calendar.ex
+++ b/lib/cocktail/builder/i_calendar.ex
@@ -5,6 +5,8 @@ defmodule Cocktail.Builder.ICalendar do
   TODO: write long description
   """
 
+  import Cocktail.Util
+
   alias Cocktail.{Rule, Schedule, Validation}
   alias Cocktail.Validation.{Day, DayOfMonth, HourOfDay, Interval, MinuteOfHour, SecondOfMinute, TimeOfDay, TimeRange}
 
@@ -106,7 +108,7 @@ defmodule Cocktail.Builder.ICalendar do
 
   defp build_end_time(%Schedule{start_time: start_time, duration: duration}) do
     start_time
-    |> Timex.shift(seconds: duration)
+    |> shift_time(seconds: duration)
     |> build_time("DTEND")
   end
 
diff --git a/lib/cocktail/schedule_state.ex b/lib/cocktail/schedule_state.ex
index 0d257ff..492371a 100644
--- a/lib/cocktail/schedule_state.ex
+++ b/lib/cocktail/schedule_state.ex
@@ -2,6 +2,7 @@ defmodule Cocktail.ScheduleState do
   @moduledoc false
 
   alias Cocktail.{RuleState, Schedule, Span}
+  import Cocktail.Util
 
   @type t :: %__MODULE__{
           recurrence_rules: [RuleState.t()],
@@ -114,7 +115,7 @@ defmodule Cocktail.ScheduleState do
       | recurrence_rules: rules,
         recurrence_times: times,
         exception_times: exceptions,
-        current_time: Timex.shift(time, seconds: 1)
+        current_time: shift_time(time, seconds: 1)
     }
 
     {occurrence, new_state}
@@ -122,7 +123,7 @@ defmodule Cocktail.ScheduleState do
 
   @spec span_or_time(Cocktail.time() | nil, pos_integer | nil) :: Cocktail.occurrence()
   defp span_or_time(time, nil), do: time
-  defp span_or_time(time, duration), do: Span.new(time, Timex.shift(time, seconds: duration))
+  defp span_or_time(time, duration), do: Span.new(time, shift_time(time, seconds: duration))
 
   @spec min_time_for_rules([RuleState.t()]) :: Cocktail.time() | nil
   defp min_time_for_rules([]), do: nil
diff --git a/lib/cocktail/util.ex b/lib/cocktail/util.ex
index 637e86b..21a85f5 100644
--- a/lib/cocktail/util.ex
+++ b/lib/cocktail/util.ex
@@ -3,4 +3,26 @@ defmodule Cocktail.Util do
 
   def next_gte([], _), do: nil
   def next_gte([x | rest], search), do: if(x >= search, do: x, else: next_gte(rest, search))
+
+  def beginning_of_day(time) do
+    time
+    |> Timex.beginning_of_day()
+    |> no_ms()
+  end
+
+  def beginning_of_month(time) do
+    time
+    |> Timex.beginning_of_month()
+    |> no_ms()
+  end
+
+  def shift_time(datetime, opts) do
+    datetime
+    |> Timex.shift(opts)
+    |> no_ms()
+  end
+
+  def no_ms(time) do
+    Map.put(time, :microsecond, {0, 0})
+  end
 end
diff --git a/lib/cocktail/validation/day_of_month.ex b/lib/cocktail/validation/day_of_month.ex
index acbaf8f..8c2d78a 100644
--- a/lib/cocktail/validation/day_of_month.ex
+++ b/lib/cocktail/validation/day_of_month.ex
@@ -2,7 +2,7 @@ defmodule Cocktail.Validation.DayOfMonth do
   @moduledoc false
 
   import Cocktail.Validation.Shift
-  import Cocktail.Util, only: [next_gte: 2]
+  import Cocktail.Util
 
   # assumed that DST can not "take" more than 4 hours between any 2 consecutive days
   @min_dst_resultant_hours 20
@@ -28,9 +28,7 @@ defmodule Cocktail.Validation.DayOfMonth do
       case next_gte(normalized_days, current_day_of_month) do
         # go to next month
         nil ->
-          next_month_time =
-            time
-            |> Timex.shift(months: 1)
+          next_month_time = shift_time(time, months: 1)
 
           next_month_normalized_days = Enum.map(days, &normalize_day_of_month(&1, next_month_time))
           next_month_earliest_day = Timex.set(next_month_time, day: hd(Enum.sort(next_month_normalized_days)))
diff --git a/lib/cocktail/validation/interval.ex b/lib/cocktail/validation/interval.ex
index 17a8c91..4f5ca43 100644
--- a/lib/cocktail/validation/interval.ex
+++ b/lib/cocktail/validation/interval.ex
@@ -3,6 +3,7 @@ defmodule Cocktail.Validation.Interval do
 
   import Integer, only: [mod: 2, floor_div: 2]
   import Cocktail.Validation.Shift
+  import Cocktail.Util
 
   @typep iso_week :: {Timex.Types.year(), Timex.Types.weeknum()}
 
@@ -20,8 +21,8 @@ defmodule Cocktail.Validation.Interval do
 
   def next_time(%__MODULE__{type: :monthly, interval: interval}, time, start_time) do
     start_time
-    |> Timex.beginning_of_month()
-    |> Timex.diff(Timex.beginning_of_month(time), :months)
+    |> beginning_of_month()
+    |> Timex.diff(beginning_of_month(time), :months)
     |> mod(interval)
     |> shift_by(:months, time)
   end
diff --git a/lib/cocktail/validation/schedule_lock.ex b/lib/cocktail/validation/schedule_lock.ex
index 72fd331..5769e63 100644
--- a/lib/cocktail/validation/schedule_lock.ex
+++ b/lib/cocktail/validation/schedule_lock.ex
@@ -3,6 +3,7 @@ defmodule Cocktail.Validation.ScheduleLock do
 
   import Integer, only: [mod: 2]
   import Cocktail.Validation.Shift
+  import Cocktail.Util
 
   @type lock :: :second | :minute | :hour | :wday | :mday
 
@@ -34,7 +35,7 @@ defmodule Cocktail.Validation.ScheduleLock do
 
   def next_time(%__MODULE__{type: :mday}, time, start_time) do
     if start_time.day > Calendar.ISO.days_in_month(time.year, time.month) do
-      next_time(%__MODULE__{type: :mday}, Timex.shift(time, months: 1), start_time)
+      next_time(%__MODULE__{type: :mday}, shift_time(time, months: 1), start_time)
     else
       next_mday_time(%__MODULE__{type: :mday}, time, start_time)
     end
@@ -56,7 +57,7 @@ defmodule Cocktail.Validation.ScheduleLock do
           |> Timex.diff(time, :days)
 
         start_time_day_of_month ->
-          next_month_date = Timex.shift(time, months: 1)
+          next_month_date = shift_time(time, months: 1)
           # Timex.set already handle the marginal case like setting a day of month more than the month contains
           next_month_date
           |> Timex.set(day: start_time_day_of_month)
diff --git a/lib/cocktail/validation/shift.ex b/lib/cocktail/validation/shift.ex
index 3e163f8..1c5c766 100644
--- a/lib/cocktail/validation/shift.ex
+++ b/lib/cocktail/validation/shift.ex
@@ -9,7 +9,7 @@ defmodule Cocktail.Validation.Shift do
 
   @typep option :: nil | :beginning_of_day | :beginning_of_hour | :beginning_of_minute
 
-  import Timex, only: [shift: 2, beginning_of_day: 1]
+  import Cocktail.Util
 
   @spec shift_by(integer, shift_type, Cocktail.time(), option) :: result
   def shift_by(amount, type, time, option \\ nil)
@@ -18,7 +18,7 @@ defmodule Cocktail.Validation.Shift do
   def shift_by(amount, type, time, option) do
     new_time =
       time
-      |> shift("#{type}": amount)
+      |> shift_time("#{type}": amount)
       |> apply_option(option)
 
     {:change, new_time}