Date trivia

["Less is more." <yvonne -at- VENUS -dot- SMARTSTAR -dot- COM>]

Sally Marquigny <SALLYM -at- MSMAILHQ -dot- NETIMAGE -dot- COM> said:

> These are the crazies bunch of dates I've ever seen!  The only one that
> seems to make sense is Informix.  What's significant about the other dates
> (especially Nov 17, 1858???)?  Why does Oracle feel it necessary to allow
> dates into BC/BCE?  And why did they pick 4712 BC?  Are these "inside
> jokes"?

Informix    January 1, 1 A.D.    to  December 31, 9999
    Pretty normaly sounding dates.

Ingres      January 1, 1582      to  December 31, 2382
    October 15, 1582 was the start of the Gregorian calendar.
    Their internal storage format probably runs out around 2382,
    so it may allow more precise times than other databases or
    use a smaller variable size.

Oracle      January 1, 4712 B.C. to  December 31, 4712
    In 46 B.C., Julius Caesar retroactively declared January 1, 4712
    to be the first day of the Julian calendar.

RDB         November 17, 1858    to  December 31, 9999
    November 17, 1858 is the date the Smithsonian was founded.
    I don't know why DEC chose that date.

Sybase      January 1, 1753      to  December 31, 9999
    England and its colonies switched to the Gregorian calendar
    on September 14, 1752.

This info comes from the "More on Dates" topic I recently squeezed into
our online help system. The topic discusses the history of the Julian
and Gregorian calendar. It was fun writing about something so different
from the usual software fare. I couldn't see putting it in the printed
manual since it doesn't contain any info that users "need", but I like
adding little treats for those who use my online help system.

Yvonne DeGraw
yvonne -at- smartstar -dot- com