date comparison

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: date comparison by Tanalis (Curate) on May 20, 2003 at 13:20 UTC
The way I always do this is either to use the `lt` and `gt` operators on the YYYY-MM-DD string (they'll compare each digit in turn, and the hyphens will be compared simply with each other, so they won't affect the comparison), or to substitute out the hyphens, and then use normal numeric comparison. A couple examples of this are as follows: `my $date1 = "2003-05-20"; my $date2 = "2003-04-19"; if ($date1 gt $date2) { print "Date 1 is bigger" } # # # alternatively my $date1 = "2003-05-20"; my $date2 = "2003-04-19"; $date1 =~ s/\-//g; $date2 =~ s/\-//g; if ($date1 > $date2) { print "Date 1 is bigger" }` [download] Hope that helps. -- Foxcub `#include www.liquidfusion.org.uk`	[reply] [d/l] [select]
Re: date comparison by Joost (Canon) on May 20, 2003 at 13:37 UTC
The above suggestions are correct for just sorting dates, but if you need to know the difference between dates you need to use another approach: Lowlevel approach: You can use ~~POSIX's strftime() function~~ Time::Local's timelocal() function to convert dates to epoch seconds, and substract them, but if you need to convert the difference in seconds back to anything more complicated than 24 hour days, you probably need something more high-level. use CPAN You can also take a look at the (literally) hundreds of CPAN date modules. One you can probably use is Date::Calc. Joost update: finally found the right standard module to convert back from localtime. `-- #!/usr/bin/perl -np BEGIN{@ARGV=$0}s(^([^=].*)\|=)()s; =Just another perl hacker\` [download]	[reply] [d/l]
Re: date comparison by fglock (Vicar) on May 20, 2003 at 14:46 UTC
See also http://datetime.perl.org	[reply]
Re: date comparison by arthas (Hermit) on May 20, 2003 at 14:01 UTC
You can use Date::Manip to obtain the delta between one date and the other. Here's an example: `use Date::Manip; $date1=&ParseDate('2004-10-28'); $date2=&ParseDate('2003-10-23'); $delta=&DateCalc($date1,$date2,\$err,1); print $delta."\n";` [download] The content of $delta is a string which you have to know how to read. The format is: `YY:MM:WK:DD:HH:MM:SS (the years, months, etc. between the two)` [download] Actually, there are several options for date comaprison. Read perldoc Date::Manip for more information. Michele.	[reply] [d/l] [select]
Re: Re: date comparison by TVSET (Chaplain) on May 20, 2003 at 14:42 UTC
From the rumors I've heard, Date::Manip is considered to be slow and heavy. You might gain something by splitting the date into year, month, and date and feeding it to `Date_to_Time` sub from the Date::Calc module. Works like a charm too, you know. :) Leonid Mamtchenkov aka TVSET	[reply] [d/l]
Re: date comparison by Thelonius (Priest) on May 20, 2003 at 13:18 UTC
gt, ge, lt, le, ne, eq, cmp	[reply]

Lowlevel approach:

use CPAN