epoch Prime

[Dieter]

(01-05-2018 09:36 PM)salvomic Wrote:  I modified Bill's program changing the second instruction from -18000 to +3600 trying to get UTC+1 (instead of his statement; Bill in that thread wrote: «Seconds relative to GMT. Time zone given is Eastern Standard Time») and the result of EPOCH in HP41CX is equal to that in this web site
, so I think it return GMT value and not local time...
The Prime returns one hour more, that should be the real local time.

Taking a look at Bill's program it becomes clear that the time zone is subtracted at the end of the calculation. This means: you enter a time in your local time zone (or have the calculator take the current date/time from its clock) and the resulting epoch value refers to UTC (or GMT, if you prefer). So it is clear why Bill's EPOCH program returns 3600 seconds less.

As far as I know Unix time indeed refers to UTC, so this is the correct way to handle this. You may do so as well and subtract your local timezone (+3600 s) at the end.

Dieter