How to calculate seconds elapsed since 00:00:00 GMT January 1, 1970?

Here's a little utility .axi defining a "DateTime" structure with associated functions working on it, one of them being the difference in seconds between two dates.

STACK_VAR _DateTime now, y0;
STACK_VAR LONG theResult;

DateTime_Now(now);
DateTime_SetDate(y0, 1970, 1, 1)
DateTime_SetTime(y0, 0, 0, 0)
theResult = DateTime_GetDiffSeconds(now, y0)

Doing the reverse:

//assume theSecs contains the seconds...
STACK_VAR _DateTime theResult;

DateTime_SetDate(theResult, 1970, 1, 1)
DateTime_SetTime(theResult, 0, 0, 0)
DateTime_SecondOffset(theResult, theSecs)

// Now use theResult, f.e. using DateTime_GetDateTimeString()...

It is not very well documented, but fire away if you have a question. One thing you need to do in the CALLING code is to define the functions you are actually using. The .axi figures out by itself which internal ones are needed if any. For example:

#define __DATETIME_SecondOffset__

In any case Netlinx will remind you some function is not defined. Alternatively uncomment all such defines in the .axi. I do this to keep the code size down, I am reaching 1MB and the limit of my old Netlinx card...

Credit where credit is due: part of this code is derived from Jeff's code on sourceforge, in particular the stuff dealing with calculations of seconds since 1900...

Hope this helps

Fred