What is the recommended way of doing date arithmetics in Perl开发者_C百科?
Say for example that I want to know the date three days ago from today (where today
= 2010-10-17
and today - 3 days
= 2010-10-13
). How would you do that in Perl?
You can use DateTime and DateTime::Duration
http://search.cpan.org/dist/DateTime/lib/DateTime/Duration.pm
Or work with unix timestamps:
my $now = time();
my $threeDaysAgo = $now - 3 * 86400;
my ($day, $mon, $year) = (localtime($threeDaysAgo))[3, 4, 5];
printf("Three days ago was %04d-%02d-%02d", $year+1900, $mon+1, $day);
See DateTime on CPAN (or here).
There are many, many different date and time manipulation modules.
These include:
- Date::Calc - and the Add_Delta_Days function
- Date::Manip - and the DateCalc function
- DateTime
All of these are well thought of. There are many others in addition. A lot depends on the sort of arithmetic you want to do. DateTime is perhaps the most rigorous, but Date::Calc and Date::Manip may be easier to handle for the work you need.
This is by far the module with the most functionality that I've come across: Date::Manip
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