By my calculation (which may well be wrong), subtracting 24 to determine yesterday's date is wrong during one one-hour period per year, and adding 24 hours to determine tomorrow's date is wrong during a second one-hour period, each period corresponding to one of the adjustments.

If I'm wrong, please set me straight.

Updated:

I wasn't 100% sure I was right, so I did a bit of research and an experiment with Time::Local. At least in most of the U.S. (there are exceptions, dammit), we do the daylight savings switch by either repeating 1-2am on the first Sunday of April, by by skipping from 1:59:59 to 3:00:00am on the last Sunday of October. In either case, it's save to subtract 24 hours from the current time for the purposes of determining the previous date.

Nope, I was right the first time.

In reply to Re: Re: Re: Re: Date by dws
in thread How to find yesterdays date (was: Date) by Anonymous Monk

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