This program will be helpful if someone want to create recur date patterns based on criteria (yearly, monthly,weekly and daily). Program is written in Perl using old version of Date::Manip CPAN module.

```
# Script to calculate recurrence dates based on given criteria using Perl Date::Manip module.
# All the input dates in this are given hard coded. These shall be passed through external program etc.
``````
#!/usr/local/bin/perl -w
use strict;
use Date::Manip;
use Data::Dumper;
# calculate the dates for yearly patterns.
&yearly();
&monthly();
&weekly();
&daily();
sub yearly {
my $base = "2015-10-29";
my $start_date = "2015-10-29";
my $end_date = "2018-01-01";
my $yearly_recur_every ="1";
my $yearly_on_month = "10";
my $yearly_on_week = "0";
my $yearly_on_day = "29";
my $yearly_on_the_month = "10";
my $yearly_on_the_week = "1";
my $yearly_on_the_day = "1";
my $frequency = "";
my $frequency_pattern_yearly_on = "$yearly_recur_every*$yearly_on_month:$yearly_on_week:$yearly_on_day:0:0:0";
my $frequency_pattern_yearly_on_the = "$yearly_recur_every*$yearly_on_the_month:$yearly_on_the_week:$yearly_on_the_day:0:0:0";
my @yearly_dates_on = ParseRecur($frequency_pattern_yearly_on,$base,$start_date,$end_date); # On a certain day of a month
my @yearly_dates_on_the = ParseRecur($frequency_pattern_yearly_on_the,$base,$start_date,$end_date); # First Monday of Oct
print "\n";
print "******************************************************************************\n";
print "**************************** YEARLY *******************************************\n";
print "*******************************************************************************\n";
print "Start date :". $start_date."\n";
print "End date :". $end_date."\n";
print "\n";
print "******************************************************************************\n";
print "Temporal expression: every 1 year on October 29\n";
print "Rule: ".$frequency_pattern_yearly_on;
print "\n";
print "Dates:\n";
print Dumper (\@yearly_dates_on);
print "\n";
print "Temporal expression: every 1 year on the first Monday of October\n";
print "Rule: ".$frequency_pattern_yearly_on_the;
print "\n";
print "Dates:\n";
print Dumper (\@yearly_dates_on_the);
print "\n";
}
# Monthly
sub monthly () {
my $base = "2015-10-29";
my $start_date = "2016-01-22";
my $end_date = "2017-06-01";
my $monthly_recur_every ="1";
my $monthly_day_of = "29";
my $monthly_the_day = "1";
my $monthly_the_week = "1";
my $frequency = "";
my $frequency_pattern_monthly_day = "0:$monthly_recur_every*0:$monthly_day_of:0:0:0";
my $frequency_pattern_monthly_the_day ="0:1*-2:5:0:0:0"; # Every month on the 2nd last Friday
my @monthly_dates_day = ParseRecur($frequency_pattern_monthly_day,$base,$start_date,$end_date); # On a certain day of a month
my @monthly_dates_the_day = ParseRecur($frequency_pattern_monthly_the_day,$base,$start_date,$end_date); # First Monday of Oct
print "\n";
print "******************************************************************************\n";
print "**************************** MONTHLY *******************************************\n";
print "*******************************************************************************\n";
print "Start date :". $start_date."\n";
print "End date :". $end_date."\n";
print "\n";
print "******************************************************************************\n";
print "Temporal expression: Day 29 of every 1 month\n";
print "Rule: ".$frequency_pattern_monthly_day;
print "\n";
print "Dates:\n";
print Dumper (\@monthly_dates_day);
print "\n";
print "Temporal expression: The first monday of every month\n";
print "Rule: ".$frequency_pattern_monthly_the_day;
print "\n";
print "Dates:\n";
print Dumper (\@monthly_dates_the_day);
print "\n";
}
# Weekly
sub weekly () {
my $base = "2015-10-29";
my $start_date = "2016-01-22";
my $end_date = "2016-03-01";
my $weekly_recur_every ="1";
# We need to add comma on the value we are getting from UI .. if the field is not selected means no value then
# no comma will be added
my $first_day_of_the_week = ""; # Monday
my $second_day_of_the_week = "2,"; # Tuesday
my $third_day_of_the_week = ""; # Wednesday
my $fourth_day_of_the_week = "4,"; #Thrusday
my $fifth_day_of_the_week = ""; # Friday
my $sixth_day_of_the_week = ""; # Saturday
my $seventh_day_of_the_week = ""; # Sunday
# my $weekly_the_day = "1";
# my $weekly_the_week = "1";
my $frequency = "";
my $frequency_pattern_weekly_day = "0:0:$weekly_recur_every*$first_day_of_the_week$second_day_of_the_week$third_day_of_the_week$fourth_day_of_the_week$fifth_day_of_the_week$sixth_day_of_the_week$seventh_day_of_the_week:0:0:0";
my @weekly_dates_day = ParseRecur($frequency_pattern_weekly_day,$base,$start_date,$end_date); # On a certain day of a month
print "\n";
print "******************************************************************************\n";
print "**************************** WEEKLY *******************************************\n";
print "*******************************************************************************\n";
print "Start date :". $start_date."\n";
print "End date :". $end_date."\n";
print "\n";
print "Temporal expression: Every every week on Tuesday and Thrusday\n";
print "Rule: ".$frequency_pattern_weekly_day;
print "\n";
print "Dates:\n";
print Dumper (\@weekly_dates_day);
print "\n";
}
# Daily
sub daily () {
my $base = "2015-10-29";
my $start_date = "2016-01-22";
my $end_date = "2016-02-05";
my $daily_recur_everyday ="1";
# We need to add comma on the value we are getting from UI .. if the field is not selected means no value then
# no comma will be added
my $first_day_of_the_weekday = "1,"; # Monday
my $second_day_of_the_weekday = "2,"; # Tuesday
my $third_day_of_the_weekday = "3,"; # Wednesday
my $fourth_day_of_the_weekday = "4,"; #Thrusday
my $fifth_day_of_the_weekday = "5"; # Friday
my $daily_start_time = "8:00"; # 8AM
my $frequency = "";
my $frequency_pattern_daily_everyday = "0:0:0:$daily_recur_everyday*0:0:0";
# 0:1*1-5:$dow:0:0:0";
# "0:0:0:$n*0:0:0"; # Every nth day
my $frequency_pattern_daily_every_weekday = "0:0:$daily_recur_everyday*$first_day_of_the_weekday$second_day_of_the_weekday$third_day_of_the_weekday$fourth_day_of_the_weekday$fifth_day_of_the_weekday:0:0:0";
my @daily_dates_everyday = ParseRecur($frequency_pattern_daily_everyday,$base,$start_date,$end_date); # On a certain day of a month
my @daily_dates_every_weekday = ParseRecur($frequency_pattern_daily_every_weekday,$base,$start_date,$end_date); # On a certain day of a month
print "\n";
print "******************************************************************************\n";
print "**************************** DAILY *******************************************\n";
print "******************************************************************************\n";
print "Start date: ". $start_date."\n";
print "End date: ". $end_date."\n";
print "\n";
print "Temporal expression: Everyday\n";
print "Rule: ".$frequency_pattern_daily_everyday;
print "\n";
print "Dates:".@daily_dates_everyday."\n";
print Dumper (\@daily_dates_everyday);
print "\n";
print "Temporal expression: Every weekday\n";
print "Rule: ".$frequency_pattern_daily_every_weekday;
print "\n";
print "Dates:\n";
print Dumper (\@daily_dates_every_weekday);
print "\n";
}
# End of script
```

Full working code is available on GitHub with documentation.

Enjoy,