Did your jobs run?

By on April 3, 2006

… or, “Hey, let’s start a flame war!”

Jason Kottke posted a little tidbit that the Linux evangelist in me will simple not leave lie:

If you had a job scheduled to run between 2AM and 3AM Sunday morning on a Windows server, and you observe Daylight Savings Time, it didn’t run. If you had a cron job scheduled on your Linux box, it ran at 3AM.

Now, both of these approaches have pluses and minuses. You could argue that, since 2:30 never happened, a job scheduled for that time shouldn’t run. Also, if you had dependent jobs (DL logs from server at 2:10, kick off stats parser at 2:40), something probably got monkeyed up.

Still, for 95% of all cases, the Linux approach is probably the best in this case. You’re running things at that hour because you don’t want to do them during the daytime, not because you have to run them at an exact time. And, if you’re writing time-dependent cron jobs, you’ve probably already had trouble without the help of Daylight Savings.

So, points for Linux. I just imagine a bunch of Windows sysadmins reading this right now thinking, “Oh man, what runs between two and three?!”



  1. there are actually two differences:

    1) un*xs donn’t run jobs at a particular time, but as soon as possible after that time has passed. this allows for real world time problems like the computer or the cron daemon going down.

    2) un*xs actually differentiate between standard and daylight time. it’s not so much of an issue here, but in the fall some people would claim that 1:30 occurs twice, it’s actually two different 1:30s – one for standard, and one for daylight savings. differentiating allows you to figure out which one you actually meant, and order time stamps a little bit more effectively.

    i’m not sure where windows is supposed to come out ahead in this comparison…

  2. i’m not sure where windows is supposed to come out ahead in this comparison…

    It’s not supposed to come out ahead. The Windows behavior kinda sucks. I was just trying to be nice. :-)

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