convert a time to unix timestamp

[pigsfoot]

Hi,
Is it possible to convert a time only to a unix timestamp. Everything i have found reffers to a date rather than time.

i.e. Time 00:15:00 = 1638317700

where A2 = 00:00:00 and the cell is formatted as Time

I just need a formula to work that out please.

 

[6StringJazzer]

To convert to a Unix timestamp, you have to include the date. A Unix timestamp is the number of seconds since Jan 1, 1970. Do you want to assume that your time is on the current date?

This will give the Unix timestamp for a given date+time:

Dim DateTime As Date
DateTime = Now
DateDiff("s", "1/1/1970", DateTime)

This will do it when your date is TODAY:

Dim TimeOnly As Double
TimeOnly = TimeValue("00:15:00")
DateDiff("s", "1/1/1970", Date + TimeOnly)