XT Series Timer
ChronTrol
48
User's Guide
Day-Based Programs at the End of DST
When Daylight Saving Time ends at 2 a.m. on the last Sunday in October, the
event mentioned earlier will occur when the clock reads 2:30 a.m., even
though 25 actual hours will have elapsed since its last occurrence, because
the clock fell back one hour at 2 a.m.
Also, day-based programs scheduled to occur in the hour between 1:00 a.m.
and 2:00 a.m., the “repeated hour,” will occur only once, during the first
running of that hour.
24-Hour Based Programs at the Start of DST
A program set to occur every 24 hours starting at 2:30 a.m. will continue the
24-hour cycle regardless of the clock time. On the first day of Daylight
Saving Time, the event will occur 24 hours after the last occurrence, but the
clock will read 3:30 a.m. because it advanced 1 hour at 2 a.m. The next day
the event will also occur at 3:30 a.m. and each day thereafter.
24-Hour Based Programs at the End of DST
When Daylight Saving Time ends, the event will go back to occurring when
the clock reads 2:30 a.m. because the clock fell back one hour at 2 a.m., but
there will always be 24 hours between occurrences.
How to set a Day-Based Program
A day-based program is set by leaving out the hours and minutes in the
Cycle
Length
, and using only days.
By definition, a program with
no
cycle length is a day-based program; that is,
it will repeat at the same time every day, regardless of whether the day is 23,
24, or 25 hours long.
(Remember that a program with an On Date or Off Date will repeat once
every calendar year if no cycle length is set, regardless of whether the year is
365 or 366 days long).
Sample Programs 4 through 7 illustrate applications in which events repeat at
rates other than every day. When you review the cycle length of a day-based
program, a “C” displays. This is an indication to you that, even though no
hours and minutes of the cycle have been set, cycle days
are
set.
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