VBA-UTC

UTC and ISO 8601 date conversion and parsing for VBA (Windows and Mac Excel, Access, and other Office applications).

Tested in Excel 2016 for Windows and Mac, but should apply to Windows Excel 2007+.

Example

' Timezone: EST (UTC-5:00), DST: True (+1:00) -> UTC-4:00
Dim LocalDate As Date
Dim UtcDate As Date
Dim Iso As String

LocalDate = DateValue("Jan. 2, 2003") + TimeValue("4:05:06 PM")
UtcDate = UtcConverter.ConvertToUtc(LocalDate)

Debug.Print VBA.Format$(UtcDate, "yyyy-mm-ddTHH:mm:ss.000Z")
' -> "2003-01-02T20:05:06.000Z"

Iso = UtcConverter.ConvertToIso(LocalDate)
Debug.Print Iso
' -> "2003-01-02T20:05:06.000Z"

LocalDate = UtcConverter.ParseUtc(UtcDate)
LocalDate = UtcConverter.ParseIso(Iso)

Debug.Print VBA.Format$(LocalDate, "m/d/yyyy h:mm:ss AM/PM")
' -> "1/2/2003 4:05:06 PM"