The Excel time stamp is only the time. It’s separate from the date.
Somehow I’d have to combine the two cells into a combined date/time format. Then get a Unix date.
The rub is the need for a static date. Unchanging.
Open the spreadsheet. ctrl : and then ctrl shift : stamps the date and time into the cells.
It’s like the time clock at work.
something like =Today() changes every time the spreadsheet opens
I know dates and times are stored as a number. You should be able to subtract two dates and get the elapsed days in a number.
That’s the first thing I tried with the two time cells. I got some weird answer. I had to use the =Text to get the right answer.