// returns an array with the dates for a recurring monthly rule

$dates = tscpl_recurring_monthly( $start_date, $end_date, 'fourth', 'tuesday );

function tscpl_recurring_weekly( $start_date, $end_date = null, $dow ) {

    $days = array(
        'sunday' => 0,
        'monday' => 1,
        'tuesday' => 2,
        'wednesday' => 3,
        'thursday' => 4,
        'friday' => 5,
        'saturday' => 6
        );

    $zone = date_default_timezone_get();
    date_default_timezone_set( 'America/Chicago' );

    if ( gettype( $dow ) == 'integer' )
        $dow = $days[ $dow ];

    if ( empty( $start_date ) )
        $start_date = date( 'Y-m-d' );

    $start_date = date( 'Y-m-d', strtotime( $start_date ) );
    $start_dow  = (int) date( 'w', strtotime( $start_date ) );

    if ( empty( $end_date ) ) {
        $end_date = date( 'Y-m-d', strtotime( current_time() . ' +18 weeks' ) );  // well into the next print calendar cycle
    } else {
        $end_date = date( 'Y-m-d', strtotime( $end_date ) );
    }

    if ( gettype( $dow ) == 'string' )
        $dow = $days[ strtolower( $dow ) ];

    // does our start date equal the DOW?
    if ( $start_dow < $dow ) {
        $start_date = date( 'Y-m-d', strtotime( $start_date . ' +' . ($dow - $start_dow) . ' days' ) );
    } elseif ( $start_dow > $dow ) {
        $start_date = date( 'Y-m-d', strtotime( $start_date . ' +' . (7 - $start_dow) . ' days' ) );
    }

    $i = 0;
    $dates = array();
    while ( $i < 12 ) {
        $dt = date( 'Y-m-d', strtotime( $start_date . ' +' . $i . ' weeks' ) );
        if ( $dt > $end_date )
            break;
        $dates[] = $dt;
        $i++;
    }

    date_default_timezone_set( $zone );

    return $dates;

}

function tscpl_date( $format = 'Y-m-d H:i:s', $date ) {
    if ( gettype( $date ) == 'string' )
        $date = strtotime( $date );
    return date( $format, $date );
}

function tscpl_date_by_text( $date, $text ) {
    $dt = new \DateTime( $date );
    return $dt->modify( $text )->format( 'Y-m-d 00:00:00' );
}