diff --git a/inc/RRule.php b/inc/RRule.php
index 0fd87304..822fc471 100644
--- a/inc/RRule.php
+++ b/inc/RRule.php
@@ -103,11 +103,191 @@ class iCalDate {
   }
 
 
+  /**
+  * No of days in a month 0(Jan) - 11(Dec)
+  */
+  function DaysInMonth( $mo=false, $yy=false ) {
+    if ( $mo === false ) $mo = $this->_mo;
+    switch( $mo ) {
+      0: // January
+      2: // March
+      4: // May
+      6: // July
+      7: // August
+      9: // October
+     11: // December
+        return 31;
+        break;
+
+      3: // April
+      5: // June
+      8: // September
+     10: // November
+        return 30;
+        break;
+
+      1: // February
+        if ( $yy === false ) $yy = $this->_yy;
+        if ( (($yy % 4) == 0) && ((($yy % 100) != 0) || (($yy % 400) == 0) ) ) return 29;
+        return 28;
+        break;
+
+      default:
+        dbg_error_log( "ERROR"," Invalid month of '%s' passed to DaysInMonth" );
+        break;
+
+    }
+  }
+
+
+  /**
+  * Add some number of months to a date
+  */
+  function AddMonths( $mm ) {
+    $this->_mo += $mm;
+    while ( $this->_mo < 0 ) {
+      $this->_mo += 12;
+      $this->_yy--;
+    }
+    while ( $this->_mo > 11 ) {
+      $this->_mo -= 12;
+      $this->_yy++;
+    }
+
+    if ( ($this->_dd > 28 && $this->_mo == 1) || $this->_dd > 30 ) {
+      // Ensure the day of month is still reasonable
+      $dim = $this->DaysInMonth();
+      if ( $this->_dd > $dim ) {
+        // We don't need to check for month > 12, since _dd can't be greater than 31 if it was previously valid
+        $this->_mo++;
+        $this->_dd -= $dim;
+      }
+    }
+  }
+
+
+  /**
+  * Add some integer number of days to a date
+  */
+  function AddDays( $dd ) {
+    $this->_dd += $dd;
+    while ( 1 > $this->_dd ) {
+      $this->_mo--;
+      $this->_dd += $this->DaysInMonth();
+    }
+    while ( ($dim = $this->DaysInMonth()) < $this->_dd ) {
+      $this->_mo++;
+      $this->_dd -= $dim;
+    }
+  }
+
 }
 
 
 /**
-* A Class for handling Events on a calendar
+* A Class for handling Events on a calendar which repeat
+*
+* Here's the spec, from RFC2445:
+*
+     recur      = "FREQ"=freq *(
+
+                ; either UNTIL or COUNT may appear in a 'recur',
+                ; but UNTIL and COUNT MUST NOT occur in the same 'recur'
+
+                ( ";" "UNTIL" "=" enddate ) /
+                ( ";" "COUNT" "=" 1*DIGIT ) /
+
+                ; the rest of these keywords are optional,
+                ; but MUST NOT occur more than once
+
+                ( ";" "INTERVAL" "=" 1*DIGIT )          /
+                ( ";" "BYSECOND" "=" byseclist )        /
+                ( ";" "BYMINUTE" "=" byminlist )        /
+                ( ";" "BYHOUR" "=" byhrlist )           /
+                ( ";" "BYDAY" "=" bywdaylist )          /
+                ( ";" "BYMONTHDAY" "=" bymodaylist )    /
+                ( ";" "BYYEARDAY" "=" byyrdaylist )     /
+                ( ";" "BYWEEKNO" "=" bywknolist )       /
+                ( ";" "BYMONTH" "=" bymolist )          /
+                ( ";" "BYSETPOS" "=" bysplist )         /
+                ( ";" "WKST" "=" weekday )              /
+                ( ";" x-name "=" text )
+                )
+
+     freq       = "SECONDLY" / "MINUTELY" / "HOURLY" / "DAILY"
+                / "WEEKLY" / "MONTHLY" / "YEARLY"
+
+     enddate    = date
+     enddate    =/ date-time            ;An UTC value
+
+     byseclist  = seconds / ( seconds *("," seconds) )
+
+     seconds    = 1DIGIT / 2DIGIT       ;0 to 59
+
+     byminlist  = minutes / ( minutes *("," minutes) )
+
+     minutes    = 1DIGIT / 2DIGIT       ;0 to 59
+
+     byhrlist   = hour / ( hour *("," hour) )
+
+     hour       = 1DIGIT / 2DIGIT       ;0 to 23
+
+     bywdaylist = weekdaynum / ( weekdaynum *("," weekdaynum) )
+
+     weekdaynum = [([plus] ordwk / minus ordwk)] weekday
+
+     plus       = "+"
+
+     minus      = "-"
+
+     ordwk      = 1DIGIT / 2DIGIT       ;1 to 53
+
+     weekday    = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA"
+     ;Corresponding to SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY,
+     ;FRIDAY, SATURDAY and SUNDAY days of the week.
+
+     bymodaylist = monthdaynum / ( monthdaynum *("," monthdaynum) )
+
+     monthdaynum = ([plus] ordmoday) / (minus ordmoday)
+
+     ordmoday   = 1DIGIT / 2DIGIT       ;1 to 31
+
+     byyrdaylist = yeardaynum / ( yeardaynum *("," yeardaynum) )
+
+     yeardaynum = ([plus] ordyrday) / (minus ordyrday)
+
+     ordyrday   = 1DIGIT / 2DIGIT / 3DIGIT      ;1 to 366
+
+     bywknolist = weeknum / ( weeknum *("," weeknum) )
+
+     weeknum    = ([plus] ordwk) / (minus ordwk)
+
+     bymolist   = monthnum / ( monthnum *("," monthnum) )
+
+     monthnum   = 1DIGIT / 2DIGIT       ;1 to 12
+
+     bysplist   = setposday / ( setposday *("," setposday) )
+
+     setposday  = yeardaynum
+*
+* At this point we are going to restrict ourselves to parts of the RRULE specification
+* seen in the wild.  And by "in the wild" I don't include within people's timezone
+* definitions.  We always convert time zones to canonical names and assume the lower
+* level libraries can do a better job with them than we can.
+*
+* We will concentrate on:
+*  FREQ=(YEARLY|MONTHLY|WEEKLY|DAILY)
+*  UNTIL=
+*  COUNT=
+*  INTERVAL=
+*  BYDAY=
+*  BYMONTHDAY=
+*  BYSETPOS=
+*  WKST=
+*  BYYEARDAY=
+*  BYWEEKNO=
+*  BYMONTH=
+*
 *
 * @package awl
 */
@@ -119,13 +299,45 @@ class RRule {
   /** The first instance */
   var $_first;
 
+  /** The rule, in all it's glory */
+  var $_rule;
+
+  /** The rule, in all it's parts */
+  var $_part;
+
   /**#@-*/
 
   /**
   * The constructor takes a start & end date and an RRULE definition.  All of these
   * follow the iCalendar standard.
   */
-  function RRule( $start, $end, $rrule ) {
+  function RRule( $start, $rrule ) {
+    $this->_first = new iCalDate($start);
+
+    $this->_rule = $preg_replace( '/\s/m', '', $rrule);
+    if ( substr($this->_rule, 0, 6) = 'RRULE:' ) {
+      $this->_rule = substr($this->_rule, 6);
+    }
+    $parts = split(';',$this->_rule);
+    $this->_part = array();
+    foreach( $parts AS $k => $v ) {
+      list( $type, $value ) = split( '=', $value, 2);
+      $this->_part[$type] = $value;
+    }
+
+    // A little bit of validation
+    if ( !isset($this->_part['freq']) ) {
+      dbg_error_log( "ERROR", " RRULE MUST have FREQ=value (%s)", $rrule );
+    }
+    if ( isset($this->_part['count']) && isset($this->_part['until'])  ) {
+      dbg_error_log( "ERROR", " RRULE MUST NOT have both COUNT=value and UNTIL=value (%s)", $rrule );
+    }
+    if ( isset($this->_part['count']) && intval($this->_part['count']) < 1 ) {
+      dbg_error_log( "ERROR", " RRULE MUST NOT have both COUNT=value and UNTIL=value (%s)", $rrule );
+    }
+    if ( !preg_match( '/(YEAR|MONTH|WEEK|DAI)LY/', $this->_part['freq']) ) {
+      dbg_error_log( "ERROR", " RRULE Only FREQ=(YEARLY|MONTHLY|WEEKLY|DAILY) are supported at present (%s)", $rrule );
+    }
   }
 
   function GetNext( $after = false ) {