Adding to dates

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

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Re: Adding to dates by GrandFather (Saint) on Aug 22, 2006 at 23:53 UTC
There are a slew of modules available to do date calculations. The Swiss army chainsaw date module is Date::Manip. Date::Calc however provides Add_Delta_YM which "can be used to add a year and/or month offset to a given date" and "this function does no ``wrapping'' into the next month ... it simply truncates the day to the last possible day of the resulting month". Store the start date and add n months to get the next update date to avoid the truncation issue. DWIM is Perl's answer to Gödel	[reply]
Re: Adding to dates by explorer (Chaplain) on Aug 23, 2006 at 02:08 UTC
Solved with Date::Manip, for example: `#!/usr/bin/perl -l use Date::Manip; my $date = ParseDate("01/31/07"); my @dates = ParseRecur("0:1:0*-1:0:0:0",$date,$date,"01/31/08"); foreach ( @dates ) { print UnixDate $_,"%D"; }` [download] Output: 01/31/07 02/28/07 03/31/07 04/30/07 05/31/07 06/30/07 07/31/07 08/31/07 09/30/07 10/31/07 11/30/07 12/31/07	[reply] [d/l]
Re: Adding to dates by explorer (Chaplain) on Aug 23, 2006 at 02:29 UTC
And this is a DateTime solution: `#!/usr/bin/perl -l use DateTime; use DateTime::Duration; my $date = DateTime->new( year => 2006, month => 12, day => 31, locale => 'en_US', ); my $duration = DateTime::Duration->new( months => 1, end_of_month => 'preserve', ); for ( 1..12 ) { $date->add( $duration ); # One month more print $date->mdy('/'); # And show it }` [download] Updated: With Ponky advice, rest: `use DateTime; my $date = DateTime->last_day_of_month( year => 2006, month => 12 ); print $date->add( months => 1, end_of_month => 'preserve' )->mdy('/') +foreach 1..12;` [download]	[reply] [d/l] [select]
Re^2: Adding to dates by Ponky (Curate) on Aug 23, 2006 at 02:38 UTC
A little improvement is to include the duration definition in the add call: `$date->add( months => 1, end_of_month => 'preserve' );` [download] Then you don't need the `use DateTime::Duration` either.	[reply] [d/l] [select]
Re: Adding to dates by jdtoronto (Prior) on Aug 23, 2006 at 01:58 UTC
Over the years I have used Date::Manip as GrandFather has already suggested, currently much of my code uses Time::Piece. Others may suggest DateTime, all of these work well and each has its own advantages. If you are doing lots of commercial type calculations then Date::Calc may be what you need. Date::Manip is by far the heavy lifting champion offering far more than any of the others. But it is BIG, and by the authors own admission, slow. In fact he suggests you probably shouldn't be using it, but yu need to read the doc's just to be certain. jdtoronto	[reply]
Re^2: Adding to dates by Anonymous Monk on Aug 23, 2006 at 05:19 UTC
Thank you! That worked. Here is what I did: # $_bill is set as a fetchrow_hashref from the mysql db. ($_billUser_month,$_billUser_day,$_billUser_Year) = split /\//, $_bill +->{orig_day}, 3; $_add_Months = $_bill->{months_active} + 1; ($_billUser_Year,$_billUser_month,$_billUser_day) = Add_Delta_YM($ +_billUser_Year,$_billUser_month,$_billUser_day, 0,$_add_Months); ($_billUser_Year,$_billUser_month,$_billUser_day) = Add_Delta_Days($_b +illUser_Year,$_billUser_month,$_billUser_day, -5); $_nextBillingDate = sprintf("%02d/%02d/%02d",$_billUser_month,$_billUs +er_day,$_billUser_Year); $dbh->do(qq{UPDATE `subscription_users` SET `day` = ?, months_active = + months_active + 1 WHERE `id` = ?}, undef, $_nextBillingDate, $_billU +ser_id); [download] That way I am always basing the billing day off the original month. That way the billing DAY don't ever change, like going from 31 one month, to 30 then it would stay 30 because the next date is based on 30... Anyhow, thank you so much!! Thanks again! RJEnterprises	[reply] [d/l]