vbscript function for calculating Unix epoch, the universal machine readable timestamp.

epoch.vbs

Function UnixEpoch
	Dim utc_now, t_diff, objWMIService, colItems, item
	
	Set objWMIService = GetObject("winmgmts:" _
	    & "{impersonationLevel=impersonate}!\\.\root\cimv2")

	'Get UTC time string
	Set colItems = objWMIService.ExecQuery("Select * from Win32_UTCTime")
	For Each item In colItems
		If Not IsNull(item) Then
			utc_now = item.Month & "/" & item.Day & "/" & item.Year & " " _
	    				& item.Hour & ":" & item.Minute & ":" & item.Second
		End If
	Next
	
	'Get UTC offset, not constant due to daylight savings
	t_diff = Abs(DateDiff("h", utc_now, Now()))
	
	'Calculate seconds since start of epoch
	UnixEpoch = DateDiff("s", "01/01/1970 00:00:00", DateAdd("h",t_diff,Now()))
End Function

FYI - there is one place that use an offset that is not in whole hours ... from https://www.timeanddate.com/time/dst/
"Not Always One Hour
Today clocks are almost always set one hour back or ahead.

However, on Lord Howe Island, Australia, clocks are set only 30 minutes forward from LHST (UTC+10:30) to LHDT (UTC+11) during DST.

30 and 45 minute time zones

Throughout history, there have been several variations, like half adjustments (30 minutes) or double adjustment (2 hours). Adjustments of 20 and 40 minutes have also been used."

So ... probably better to use "s" in lines 17 and 20

Also ... I just had an odd result on 3rd April 2019 ... in Europe that is 03/04/2019 ... which would be presented in US format as 04/03/2019.
So - I suspect that it would be safer to change line 11 to put in y/m/d format with the hope that VBScript would spot the 4 digit year and the take the next number as month regardless of US/EU date format.