#!/usr/bin/perl
##############################################
#######    ii.pl     #########################
##############################################
# This program lists all dates from 01/01/1896 
#	to 12/31/2009.
# The list will be used to submit each date on 
#	the wx station site in order to gather 
#	the required data.
##############################################
# COMMENTS COME AFTER THE LINE OF INTEREST

use strict;
# to ensure scoping obedience
use warnings;
# provides warnings when syntax is off
use diagnostics;
# helps
use Number::Ops qw(:all);
# for using 'isint()' operator when determining leap years


my (@nonleaps, @leaps, @dates);
# arrays to hold non leap years, leap years, and then all dates

my @yrs = (1896 .. 2009);
# all years in the period of record (POR)

my @mos = ('01', '02', '03', '04', '05', '06', '07', '08', '09',
			10, 11, 12);
# literal strings must be used for months 1 through 9 because
# 	the web form requires input of 8 characters only (YYYYMMDD)

my @feb = ('01', '02', '03', '04', '05', '06', '07', '08', '09',
			10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 
			23, 24, 25, 26, 27, 28);
# days in the month of feb on non leap years. Literal strings
# 	used for the first 9 days for the same reason as above.

my @leap = ('01', '02', '03', '04', '05', '06', '07', '08', '09',
			10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 
			23, 24, 25, 26, 27, 28, 29);
# feb days during leap years

my @thirty = ('01', '02', '03', '04', '05', '06', '07', '08', '09',
			10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 
			23, 24, 25, 26, 27, 28, 29, 30);
# for those months with 30 days

my @thirtyone = ('01', '02', '03', '04', '05', '06', '07', '08', '09',
			10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 
			23, 24, 25, 26, 27, 28, 29, 30, 31);
# for those with 31 days

#BEGIN FLOW CONTROL#
####################
foreach my $yrs (@yrs)			
{# for each year								
	foreach my $mos (@mos)		 	
	{# for each month in each year
		if (isint($yrs/4) && $yrs != 1900)
		{# if it's a leap year	
			if ($mos=='02')
			{# if it's feb in a leap year
				foreach my $leap (@leap)
				{# then add each day in feb to the date below
					my $date = "$yrs$mos$leap";# date is YYYYMMDD
					push (@dates, "$date\n");  # add the date to the array
				}
			}
			elsif ($mos=='04' || $mos=='06' || $mos=='09' || $mos==11)
			{# if it's april, june, sept, or nov 
				foreach my $thirty (@thirty)
				{# add thirty days to each month
					my $date = "$yrs$mos$thirty";# date is YYYYMMDD
					push (@dates, "$date\n");	 # add the date to the array
				}
			}
			else
			{# if its any of the other months
				foreach my $thirtyone (@thirtyone)
				{# add 31 days
					my $date = "$yrs$mos$thirtyone";
					push (@dates, "$date\n");
				}
			}
		}
		else
		{# if it's not a leap year..(do the same, but 28 days in feb)...
			if ($mos=='02')
			{
				foreach my $feb (@feb)
				{
					my $date = "$yrs$mos$feb";
					push (@dates, "$date\n");
				}
			}
			elsif ($mos=='04' || $mos=='06' || $mos=='09' || $mos==11)
			{
				foreach my $thirty (@thirty)
				{
					my $date = "$yrs$mos$thirty";
					push (@dates, "$date\n");
				}
			}
			else
			{
				foreach my $thirtyone (@thirtyone)
				{
					my $date = "$yrs$mos$thirtyone";
					push (@dates, "$date\n");
				}
			}
		}
	}
}


print @dates;

open (FH, ">dates.txt");# open a new file for output
print FH @dates;# print the array of all dates to the file