MRC%PANDA@SUMEX-AIM.Stanford.EDU (04/02/87)
I fixed the summer time problem in TOPS-20 at about the same time
all the messages were flying on Unix-Wizards about it. The vendor-
supplied code had three cells; a tri-state flag (never summer time,
always summer time, and use algorithm), a last possible day of year to
start summer time, and a last possible day of year to end it. I added
a vector of "years when rule effective", and made the two day cells be
parallel vectors. Finally, I made the code run down the year vector
to get the right index into the day vectors.
This took me less than an hour of work. Most of it was spent
writing documentation so some poor schmuck who has to add a new rule
in the future would know what to do (nominally, add a single line such
as DST 1993,LSTMAR,FSTNOV if Congress slides it a week each way from
the current rule in 1993). This was in assembly language to boot.
It is unbelievable that any competant vendor could possibly spend
much more time fixing Unix (in C) or VMS (in BLISS). Good gawd, if I
spent a day on it I could implement a full summer time engine that let
you say which day of the week and add special year-based rules (such as
the proposed rule to end PDT a week later on presidential election
years). I guess that'd take half a day. I could spend the second half
adding rules for all our non-North American friends.
Any vendor who says that it will take time off from fixing bugs is
making an excuse. I seriously question the competancy of ANY vendor who
cannot at least provide the customer with a bare bones facility to set
summer time to fit local rules.
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