+<title>PeriodiCalendar</Title>
+<h1>PeriodiCal</h1>
+<small>Calendar with period highlighting ability</small>
+<?php if(!isset($_GET['last'])) { ?>
+<form action="?" method="GET">
+ Last: <input type="text" name="last" value="2010-01-20" title="YYYY-MM-DD date of last occurence" />
+ Periodicity: <input type="text" name="period" value="28" title="Periodicity of cycle in days" />
+ Duration: <input type="text" name="len" value="7" title="Days to highlight from beginning of cycle" />
+ Months: <input type="text" name="months" value="12" title="How many months you want to draw" />
+ <input type="submit" value="DRAW" />
+</form>
+
+<?php
+ echo("\n<!-- OPEN SOURCE:\n");readfile(__FILE__);echo("\n-".'->');
+} else {
+//init
+error_reporting(0);
+$day = 60*60*24;
+//get numbers
+$now = time(); $now = mktime(12, 0, 0, date('n',$now), 1, date('Y',$now));
+$last = date_parse_from_format('Y-m-d', $_GET['last']);
+$last = mktime(12, 0, 0, $last['month'], $last['day'], $last['year']);
+$period=28; if(isset($_GET['period'])) $period = $_GET['period'];
+$length=7; if(isset($_GET['len'])) $length = $_GET['len'];
+$months=12; if(isset($_GET['months'])) $months = $_GET['months'];
+
+echo('<table border=1>');
+$r = 0;
+for($i=0;$i<$months;$i++) {
+ $lm = $m = date('m',$now);
+ $mo = date('M',$now);
+ echo("<tr><td bgcolor='lightblue'><b>$m ($mo)</b></td>");
+ while($m == $lm) {
+ if(round(($now-$last)/$day)%($period) == 0) $r = $length;
+ $c = '';
+ if($r>0) $c = '#FF0000';
+ if($r==1 || $r==$length) $c = '#FF7777';
+ $r--;
+ echo("<td bgcolor='$c'>".date('d', $now).'</td>');
+ $now += $day;
+ $m = date('m',$now);
+ }
+ echo('</tr>');
+}
+echo('</table><small>You can bookmark this page it will get updated automatically each month.</small>');
+}