VBA-UTC

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

Tested in Windows Excel 2013 32-bit and 64-bit and Excel for Mac 2011, 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"