Daylight Savings and UNIX?

Anonymous asks: "My company recently asked me to write them a report on how UNIX properly handles the switch to Daylight Savings Time, and back again. When our systems administrators received the report, I was somewhat surprised. Many of them weren't aware that 'cron' would run the affected jobs twice in the fall, and not at all in the spring. Apparently, the man pages on some operating systems, like Solaris, aren't forthcoming with details. Others groups, like database administrators, are completely unaware of the differences between epoch time and wall clock time. Are even technical users ignorant on how UNIX handles time, time zones, and time conversion?"

Comments

Re:Wrong

[Col. Klink (retired)]

From my Debian Woody cron man page:

Special considerations exist when the clock is changed by less than 3 hours, for example at the beginning and end of daylight savings time. If the time has moved forwards, those jobs which would have run in the time that was skipped will be run soon after the change. Conversely, if the time has moved backwards by less than 3 hours, those jobs that fall into the repeated time will not be re-run.

I guess that's what you get....

[eclectric]

for using daylight saving time. Come to Indiana, where people are more normal, and don't try to change time itself.

Re:I guess that's what you get....

[RocketJeff]

Come to Indiana, where people are more normal, and don't try to change time itself.

I always heard that (most of) Indiana didn't change the clocks because they thought it would confuse the cows...

Why?

[Anonymous Coward]

"Are even technical users ignorant on how UNIX handles time, time zones, and time conversion?"

Why are you asking here at slashdot about the knowledge of technical users?

Daylight Savings? Blech

[Eponymous, Showered]

Just have your company relocate to Indiana. We don't need no steenking daylight savings.

Re:Grammar Nazi Time

[zsazsa]

(Joke's on me -- I misspelled asinine.)

Re:=P abcd1233243459834982

[einstein]

You reboot?

*rimshot*
--

Windoze

[linuxwrangler]

All this reminds me of the guy doing a writeup on the then-new Windows 95 years ago. He was apparently trying to get his article in on deadline when it became time to "fall back". He wrote that he was impressed by the fact that Windows told him that the time had changed back and asked if he wanted the computer's clock reset.

He answered "yes" but became rather less impressed an hour later when, once again, it asked him if the clock should be reset. For fun he kept answering yes each hour till he was done with his article.

Database, cron and other timezone problems aside, at least a properly set up *nix always knows what time it is both locally and in UTC so the other programs at least have a shot at running properly.