47.15. $setDSTStartRule

$setDSTStartRule tells the runtime system how to compute when Daylight Savings Time (DST) goes into effect each year. The format of the rule STRING s is:

monthName weekdayName occurrence timeOfDay

or:

monthName dateOfMonth timeOfDay

e.g.:

April Sunday 1 2:00

meaning the first Sunday in April at 2:00 a.m., which describes the rule in effect since 8 July 1986 in those parts of the United States that observe DST. The value of the DST start rule may be examined by $getDSTStartRule or by the MAINEX subcommand DSTSTARTRULE. MAINSAIL's time-zone-related facilities are described in more detail in Section 24.2 and in the description of MAINEX in Chapter 21 of the MAINSAIL Utilities User's Guide.

After a call to $setDSTStartRule, $timeSubcommandsSet becomes TRUE.