Subtracting minutes from a string

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

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Re: Subtracting minutes from a string ( Time::Piece->strptime ) by Anonymous Monk on Aug 15, 2013 at 13:03 UTC
turn string into numbers (time), manipulate time, turn time into string Re^2: Date plus Time sort from file ( Time::Piece->strptime/strftime example, Time::Piece `$ perl -MTime::Piece -le " my $now = localtime; print $now; print $now + + 60 * 30 " Thu Aug 15 06:03:23 2013 Thu Aug 15 06:33:23 2013` [download]	[reply] [d/l]
Re^2: Subtracting minutes from a string ( Time::Piece->strptime ) by Cristoforo (Curate) on Aug 15, 2013 at 23:15 UTC
Thank you! A new tool in my toolkit.	[reply]
Re: Subtracting minutes from a string by mtmcc (Hermit) on Aug 15, 2013 at 16:20 UTC
If it's just hours and minutes, you could write a subroutine: #!/usr/bin/perl use strict; use warnings; my $time = "12:30"; my $secondTime = minutes($time, 120); print STDERR "TIME: $time\tNEW: $secondTime\n"; sub minutes { my $extraHour = 0; my $time = $_[0]; my $minutes = $_[1]; my @time = split(/:/, $time); my $modMinutes = $minutes%60; $extraHour = 1 if $minutes > $time[1]; my $hours = $extraHour + (int($minutes/60)); my $newHour = sprintf("%02d", ($time[0] - $hours)%24); my $newMinutes = sprintf("%02d", ($time[1] - $modMinutes)%60); my $newTime = "$newHour:$newMinutes"; return $newTime; } [download] EDIT: changed extra hour.	[reply] [d/l]