in reply to OT: Crontab entry missed due to Daylight savings time?

One, you're right, it's nothing to do with Perl. ;)

Two, it's called "daylight saving time" (not savings). You make it sound like a bank where you can withdraw a little extra on a rainy day.

Three, DST in the USA jumps from 2am to 3am (occasionally called the Devil's Hour), or from 2am to 1am (occasionally called the Witch's Hour (not to be confused with the Witching Hour of midnight)).

Four, yes, some versions of the documentation for cron has included such operational notes nearly since its invention. Cron won't fire events for a time which never happened. Cron will fire events twice for times which happen twice.

This is another reason you should update your system time carefully and gradually with ntpd instead of with lurching adjustments like crontab: 11 1 * * * fixtime. If you somehow skip a whole minute, that system backup might not happen.

There are some cron-aids available which can help you. I think one is called anacron. This helps those folks who shut down their computer many nights, or fold their laptops at unpredictable times, but still want a "nightly" backup or a regular database update.

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Re: Re: OT: Crontab entry missed due to Daylight savings time?
by DrHyde (Prior) on Apr 08, 2004 at 08:30 UTC
    And regardless of whether it's called "daylight saving time" or "daylight savings time", it is nothing of the sort, for it does not change the amount of daylight. If it were to magically store up daylight during the summer and release it over the winter so that I didn't have to get up when it was dark and get home in the dark, then the name might be more truthful, and the concept more useful.

    It's a stupid idea anyway, and there is no proof of the supposed benefits.

    </rant>

[reply]
OT: Re: Re: OT: Crontab entry missed due to Daylight savings time?
by QM (Parson) on Apr 07, 2004 at 20:51 UTC
    <anti-rant>
    Two, it's called "daylight saving time" (not savings). You make it sound like a bank where you can withdraw a little extra on a rainy day.
    Google shows 317K hits for "daylight savings time" compared to 321K hits for "daylight saving time". Given the fuzziness of Google, and the human propensity to drop the last letter of a word, you could argue either way.

    I personally have only heard "savings", and that's what I use.

    I suppose your personal usage depends on whether you prefer the verb "saving" over the noun "savings". Or if you agree with the usage problem noted in some dictionaries, then similar phrases like Woodchip Savings Area should be Woodchip Saving Area. Unless you're just stockpiling Woodchips there, and they don't actually get saved there, so it might be more accurate to describe it as a Savings Area.

    </anti-rant>

    -QM
    --
    Quantum Mechanics: The dreams stuff is made of

[reply]
      Hm, I googled for "daylight savings time" (with quotes) and I see ~299K hits. On the first page of hits, all but one of the titles were in the singular, and three of the blurbs include a corrective note: e.g., not Daylight Savings Time.

      Also, since the USA thing is an official act of Congress, one could look up the official name of it. Saving. Each time they touched the act, on at least four different occasions, they named it in the singular.

      Though I agree that English is a "living" language, Google ain't the definitive reference of proper spelling. If so, we should all say PERL, not Perl.

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      [ e d @ h a l l e y . c c ]

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