Daylight saving time in Germany

[Darrell Allen]

No, cron will not run the same entry twice during "fall back" from daylight to standard time.

"man cron" at look at what it says about "Ambigous time":

On the days of daylight savings (summer) time transition (in time zones and countries where daylight savings time applies), cron schedules commands differently from normal.

In the following description, an ambiguous time refers to an hour and minute that occurs twice in the same day because of a daylight savings time transition (usually on a day during the Autumn season). A nonexistent time refers to an hour and minute that does not occur because of a daylight savings time transition (usually on a day during the Spring season). DST-shift refers to the offset that is applied to standard time to result in daylight savings time. This is normally one hour, but can be any combination of hours and minutes up to 23 hours and 59 minutes (see tztab(4)).

When a command is specified to run at an ambiguous time, the command is executed only once at the first occurrence of the ambiguous time.


Darrell