3/10 How does the unix cron implementation deal with daylight savings?
Officially we need to change the time at exactly 2:00am. So let's say
we have a cron job at 1:30am that has been executed, and at 2:00am
we turn it back to 1:00am. Will that particular job get executed
again? Conversely, let's say a cronjob at 2:30am was suppose to be
executed but when we spring forward to 3:00am, will that job be
ignored completely?
\_ This makes me ponder just what timezone the 'cron' daemon is
operating under. The system default? What if a user wanted to
'localize' their own crontab to their personal timezone?
\_ Quick googling shows that different UNIX handle them differently,
and even different distros handle them differently. For example,
IBM's AIX page says that jobs in ambiguous time will get run
twice and jobs in non-existent time will not get run. HP unix
doc says ambiguous time jobs will get run once only, and
non-existent time jobs will run once in the right time before the
DST change. GIYF (Google Is Your Friend). Soda MOTD is more
like your enemy, I guess. |