|Summary:||cron skips jobs on first day of DST|
|Product:||[Retired] Red Hat Linux||Reporter:||hargrove|
|Component:||vixie-cron||Assignee:||Crutcher Dunnavant <crutcher>|
|Status:||CLOSED CURRENTRELEASE||QA Contact:|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2001-04-10 22:01:46 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
Description hargrove 1999-04-04 20:04:17 UTC
Because the clock doesn't pass through the times 2:00-2:59 on the first day of daylight savings time, jobs (such as my daily backups!) that are scheduled to begin anytime in this one hour window are skipped. Arguably this is correct in the sense that these times don't exist, but if this behavior is to be considerd "normal", then the man page should warn users about this.
Comment 1 David Lawrence 1999-04-06 19:53:59 UTC
Your suggestion has been passed on to a developer for further review.
Comment 2 Michael K. Johnson 1999-04-14 17:17:59 UTC
I have reviewed the Single Unix Specification definition of crontab (it doesn't talk about cron specifically, but the crontab definition talks about the crontab format as well) and there is no indication that cron should magically re-schedule jobs that are scheduled for a non-existant time. Indeed, it is not clear what the right thing to do would be if cron tried to shuffle the schedules. I have reclassified this bug report as a documentation bug report and we'll change the man page to explicitly mention that cron will not run jobs during times that do not exist, such as during daylight savings time conversions.
Comment 3 Michael K. Johnson 1999-04-14 17:40:59 UTC
Man page updated with this information in vixie-cron-3.0.1-32
Comment 4 Jeremy Sanders 2002-11-22 12:41:41 UTC
Following up on this, in RedHat 7.3, the cron manpage makes no mention of daylight saving time. It is not clear whether some jobs may be run twice or not at all.