epoch Prime

[salvomic]

nobody fo you said me that I made an "old error of mine": to use 84600 instead of 86400!
I made this error in some astronomical programs and then I was aware of the bug after ...days... :-(

Ok, this version should work, but with some caveat:
• epoch(da, ti, zone) : input -1 for current date and also for current time, zone: 0 UTC (GMT), 1, -1 and so on...; otherwise input time as 12°30'40'' and date as 2018.0106
• epoch2date(epoc, zone) : returns date and time (as HMS)
• epoch() is here always UTC, not local time even if the time in input is local.

Code:


// Epoch Unix time from 1970 Jan 1. Inspired by a Bill Duncan's program for HP-41CX
// Thanks to Dieter, Didier Lachieze, Stephen G1CMZ, pier4r...

// Epoch seconds in UTC time
// Input: da = date (i.e. 2018.0523), ti = time (i.e. 13°15'30''), zone UTC (0 GMT)
// -1 as current date and current time
EXPORT epoch(da,ti, zone)
BEGIN
IF da==-1 THEN da:=Date; END;
IF ti==-1 THEN ti:=Time; ELSE ti:=HMS→(ti); END;
ti:=ti-zone;
RETURN 86400*(DDAYS(1970.0101,da))+3600*HMS→(ti);
END;

EXPORT epoch2date(epoc, zone)
BEGIN
local da, ti;
epoc:=epoc+3600*zone;
da:=DATEADD(1970.0101, IP(epoc/86400));
ti:=(epoc MOD 86400)/3600;
RETURN({da, →HMS(ti)});
END;

Again, it would be better to have optional input, instead of remembering to put some "magic numbers" as -1 ...

Other help much appreciated

Salvo