DateTime::Event::Cron is a DateTime extension for generating recurrence sets from crontab lines and files.

SYNOPSIS

use DateTime::Event::Cron;

# DateTime::Set construction from crontab line
$crontab = */3 15 1-10 3,4,5 */2;
$set = DateTime::Event::Cron->from_cron($crontab);
$iter = $set->iterator(after => DateTime->now);
while (1) {
my $next = $iter->next;
my $now = DateTime->now;
sleep(($next->subtract_datetime_absolute($now))->seconds);
# do stuff...
}

# List of DateTime::Set objects from crontab file
@sets = DateTime::Event::Cron->from_crontab(file => /etc/crontab);
$now = DateTime->now;
print "Now: ", $now->datetime, "n";
foreach (@sets) {
my $next = $_->next($now);
print $next->datetime, "n";
}

# DateTime::Set parameters
$crontab = * * * * *;

$now = DateTime->now;
%set_parms = ( after => $now );
$set = DateTime::Event::Cron->from_cron(cron => $crontab, %set_parms);
$dt = $set->next;
print "Now: ", $now->datetime, " and next: ", $dt->datetime, "n";

# Spans for DateTime::Set
$crontab = * * * * *;
$now = DateTime->now;
$now2 = $now->clone;
$span = DateTime::Span->from_datetimes(
start => $now->add(minutes => 1),
end => $now2->add(hours => 1),
);
%parms = (cron => $crontab, span => $span);
$set = DateTime::Event::Cron->from_cron(%parms);
# ...do things with the DateTime::Set

# Every RTFCT relative to 12am Jan 1st this year
$crontab = 7-10 6,12-15 10-28/2 */3 3,4,5;
$date = DateTime->now->truncate(to => year);
$set = DateTime::Event::Cron->from_cron(cron => $crontab, after => $date);

# Rather than generating DateTime::Set objects, next/prev
# calculations can be made directly:

# Every day at 10am, 2pm, and 6pm. Reference date
# defaults to DateTime->now.
$crontab = 10,14,18 * * * *;
$dtc = DateTime::Event::Cron->new_from_cron(cron => $crontab);
$next_datetime = $dtc->next;
$last_datetime = $dtc->previous;
...

# List of DateTime::Event::Cron objects from
# crontab file
@dtc = DateTime::Event::Cron->new_from_crontab(file => /etc/crontab);

# Full cron lines with user, such as from /etc/crontab
# or files in /etc/cron.d, are supported and auto-detected:
$crontab = * * * * * gump /bin/date;
$dtc = DateTime::Event::Cron->new(cron => $crontab);

# Auto-detection of users is disabled if you explicitly
# enable/disable via the user_mode parameter:
$dtc = DateTime::Event::Cron->new(cron => $crontab, user_mode => 1);
my $user = $dtc->user;
my $command = $dtc->command;

# Unparsed original cron entry
my $original = $dtc->original;