Just use

=MOD(start_time-hours/24,1)


"Amnon Wilensky" wrote in message
...
Hi,

I want to convert Israel time to U.S time. Every thing is going fine until
the number become negative. For example: if the time in Israel is 02:30
and
I want to find what is the time at New York I have to subtract 7:00 hours,
and I Excel don't calculate it.

Any help?

Thanks,

Amnon