There's no built in function.
I wonder if there's a web site with the necessary API (one that works like google maps) where you can use a web viewer with a URL that includes the zipcode to show a timezone in the web viewer. If so, it might be possible to "scrape" this data from the web site.
And note that daylight savings time--which is not used uniformly in all locations, will complicate your results.
Yes, I have been looking for something like google maps for the solution. Smart phones have this function. Should work in FileMaker. I'll look again.
Another interesting option might be to look for a site that lists zipcodes and timezones. If you can then download that data, you could import it into FileMaker to set up a look up table where you can enter a zipcode to get a timezone. Then you can use your system clock's time in a calculation to compute the time in the other zipcode. But you'd first need that data in a table in FileMaker...
I found a spreadsheet that has City, State, Zip and Area Code that list the TimeZone and if Daylight Savings (Y/N).
I suppose I would look for zip code and post result from TimeZone column. Just not sure how to request calculation or where to save reference data.
Any thoughts or suggestions?
I think that you'll want a table of timezones. The timezone records can then store the time difference between either you time zone or an arbitrary time zone.
Then it would work like this:
Use zipcode to look up the time zone.
Use the timezone to look up the time difference (say it's plus 1 hour).
Then use your computer's system clock to compute the time in that time zone:
Get ( CurrentTime ) + TimeDifference * 3600 // 3600 seconds = 1 hour.