Getting seconds from date

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

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Re: Getting seconds from date by bart (Canon) on Jun 05, 2011 at 11:02 UTC
`timelocal` expects a bunch of input parameters, one per date component. It's often rather easy to parse the date yourself, if it has a predefined format, and pull out individual parts. All parameters are numbers, so if you have to parse a month name, you can convert it to a month number using a small Perl data structure. If you parse a month number, be wary that `timelocal` expects the month number for January is 0. So you may have to subtract 1 to get the correct value. It's all not too much work, you can usually make it work within a couple of minutes, but if it proves to be too hard for you, you can always fall back to parsing the date using one of the (rather heavy-weight) date parsing modules, that likely can convert it to epoch seconds for you, as well.	[reply] [d/l] [select]
Re: Getting seconds from date by Corion (Patriarch) on Jun 05, 2011 at 10:16 UTC
Have you tried converting the date string you get into the format that localtime returns? It's not really hard, you just have to remember that the `localtime` API is broken and counts months from 0.	[reply] [d/l]
Re^2: Getting seconds from date by Marshall (Canon) on Jun 06, 2011 at 07:59 UTC
I think "broken" is too harsh a word. I see why this was done, so that this number can be used an index into an array of text translation values. A lot of stuff in the C library is truly ancient and predates C. Nowadays, I would imagine that location "0" would just get "burned" and not used so that the indicies have the normal human meaning. But an ancient decision made another choice. `my @monthText = qw (jan feb mar apr may jun jul aug sep oct nov dec); print "$monthText[0] is for January\n"; print "$monthText[11] is for December\n";` [download]	[reply] [d/l]
Re^2: Getting seconds from date by ultranerds (Hermit) on Jun 05, 2011 at 10:21 UTC
Hi, Thanks for the reply. I tried converting it to the localtime format, but unfortunatly didn't have much success. Do you have a module in mind to do that? TIA Andy	[reply]
Re^3: Getting seconds from date by Perlbotics (Archbishop) on Jun 05, 2011 at 10:56 UTC
Dealing with dates and times is quite tricky. Have a look at the module suggestions given in the QandASection: dates and times section, e.g. Fast(er) date parsing. However, if you insist on using Time::Local, you can use this snippet to get started... use strict; use warnings; use Time::Local qw(timelocal); sub localdate2epoch { my $date = shift; # insert some sanity checks and normalisation (whitespace removal, e +tc.) my ($year, $mon, $mday, $hour, $min, $sec) = split /[-\s:]+/, $date +; # insert more sanity checks # .oO( get the impression here, it's better to use a module ;-) $year -= 1900; # correct year (2011 = 1900 + 111); $mon -= 1; # correct month (0..11) return timelocal( $sec, $min, $hour, $mday, $mon, $year ); } my $date = "2011-06-05 11:00:00"; my $now_in_secs = localdate2epoch $date; print "In : $date\n"; print "epo: $now_in_secs\n"; print "Out: ", scalar localtime $now_in_secs, "\n"; __END__ In : 2011-06-05 11:00:00 epo: 1307264400 Out: Sun Jun 5 11:00:00 2011 [download]	[reply] [d/l]
Re^4: Getting seconds from date by ultranerds (Hermit) on Jun 05, 2011 at 11:05 UTC
Re: Getting seconds from date by Not_a_Number (Prior) on Jun 05, 2011 at 16:55 UTC
...and just to show you how easy it can be using a module (and the time() function): `use Date::Parse; print time - str2time( "2011-06-05 11:00:00" );` [download]	[reply] [d/l]