Create calendar method.

gistfile1.js

function createCalendar( year, month ){
    var calendarArray = [];
    var weekdayStrArray = [ 'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat' ];
    var monthStrArray = [ 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec' ];
    var monthArray = [ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 ];
    var monthDay = monthArray[ month - 1 ];
    var currentDay = ( new Date( year, ( month - 1 ), 1, 0, 0, 0 ) ).getDay();

    if( month == 2 )
        monthDay += year % 4 ? 0 : year % 100 ? 1 : year % 400 ? 0 : 1;

    for( var d = 1; d <= monthDay; d++ )
        calendarArray[ d + currentDay - 1 ] = d;

    // Body
    var dom_calendarBody = document.createElement( 'div' );

    // Head
    var dom_calendarHead = document.createElement( 'table' ),
        dom_calendarHeadRow = document.createElement( 'tr' ),
        dom_calendarHeadDate = document.createElement( 'th' );
    dom_calendarHeadDate.appendChild( document.createTextNode( monthStrArray[ month ] + ', ' + year ) );
    dom_calendarHead.appendChild( dom_calendarHeadRow );
    dom_calendarHead.appendChild( dom_calendarHeadDate );
    dom_calendarBody.appendChild( dom_calendarHead ); // * Append to body

    // Table
    var dom_calendarTable = document.createElement( 'table' ),
        dom_calendarTableWeekday = document.createElement( 'tr' );
    dom_calendarTable.appendChild( dom_calendarTableWeekday );
    dom_calendarBody.appendChild( dom_calendarTable ); // * Append to body

    // Set weekday title
    var dom_day;
    for( var i = 0; i < 7; i++ ){
        dom_day = document.createElement( 'th' );
        dom_day.appendChild( document.createTextNode( weekdayStrArray[ i ] ) );
        dom_calendarTableWeekday.appendChild( dom_day );
    }

    // Set days
    var day, dom_week;
    var len = calendarArray.length;
    for( i = 0; i < len; i++ ){
        if( i % 7 === 0 )
            dom_week = document.createElement( 'tr' );
        dom_day = document.createElement( 'td' );
        dom_week.appendChild( dom_day );
        day = calendarArray [ i ];
        if( day )
            dom_day.appendChild( document.createTextNode( day ) );
        if( i % 7 == 6 || i + 1 == len )
            dom_calendarTable.appendChild( dom_week );
    }

    return dom_calendarBody;
};