Re: Can I get the Day of the week?

["Simon Coulter" <shc@xxxxxxxxxxxxxxxxx>]

S
Hello  Peter,

You wrote:
>Just for fun, how about using a BIF? I have no idea if it's faster; then
>again with today's processors, speed is not always a big issue. But it's
>shorter. And by using 0001-01-01 as the base, I don't have to worry about
>negatives. However, it does return Monday as 1 instead of the more
>traditional Sunday, and I have no idea if it's correcting for dates prior to
>1533 or whenever it was that the calendar was adjusted...

The system uses a Proleptic Gregorian calendar for its date calculations.  That 
means it applies Gregorian rules to dates that are really Julian.  It doesn't 
compensate for the rules that were in force prior to 4th October 1582 (when 
the Gregorian calendar came in force -- at least in most Catholic countries) or 
prior to 2nd September 1752 for Britain or its colonies (including the USA at 
the time).

The system uses the Scaliger algorithm to calculate dates which in itself has 
an 
interesting bug.  Initialise a DATE field in RPG IV to 0300-03-01 and use debug 
to see what date actually gets stored.

Sunday is the conventional start of the week in Western countries, but the ISO 
standard pegs the start of the week as Monday.  And 0001-01-01 was actually a 
Sunday and 9999-12-31 will be a Friday (assumming there is no compensation for 
the leap year drift that will be apparent by 4000).

Watch this space for a set of date routines that does handle historical dates 
correctly ....

P.S. %REM (and its litter mate %DIV) came in at 440 for those of you 
contemplating using it.

Regards,
Simon Coulter.

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