Date Diff Text

<script type="text/javascript">
function isLeapYear( year ) {
    return ( year % 4 == 0 && ( year % 100 != 0 || year % 400 == 0 ) );
}

function daysPerMonth( year, month ) {
    daysInMonth = new Array( 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 );

    if ( month == -1 )
        month = 11

    days = daysInMonth[month];
    if ( month == 1 && isLeapYear( year ) )
        days++;

    return days;
}

function diffDateTime( dateA, dateB ) {
    maxValues = new Array( 0, 12, 0 );

    for ( i = 2; i >= 0; i-- ) {
        if ( dateA[i] < dateB[i] && i > 0 ) {
            dateA[i - 1]--;
            dateA[i] += maxValues[i] - dateB[i];
            if ( i == 2 )
                dateA[i] += daysPerMonth( dateA[0], dateA[1] );
        } else {
            dateA[i] -= dateB[i]
        }
    }

    return dateA;
}

function timeToString( value, str1, str2, str5 ) {
    if ( ! value )
        return 0;

    mod = value % 10;

    if ( value % 100 >= 10 && value % 100 <= 19 )
        return str5;

    if ( mod == 1 )
        return str1;

    if ( mod >= 2 && mod <= 4 )
        return str2;

    return str5;
}

function daysPassedText( year, month, day  ) {
    tYear  = timeToString( year, 'год', 'года', 'лет' );
    tMonth = timeToString( month, 'месяц', 'месяца', 'месяцев' );
    tDay   = timeToString( day, 'день', 'дня', 'дней' );

    preValues = new Array( year, month, day );
    preTexts = new Array( tYear, tMonth, tDay );

    numPartsPresent = 0;
    for ( i = 2; i >= 0; i-- ) {
        if ( preValues[i] !=0 )
            numPartsPresent++;
    }

    text = '';
    for ( i = 2; i >= 0; i-- ) {
        if ( preValues[i] != 0 ) {
            text = preValues[i] + ' ' + preTexts[i] + text;
            if ( numPartsPresent > 1 ) {
                text = ' и ' + text;
                numPartsPresent = 0;
            } else if ( i > 0 && preValues[i - 1] != 0 ) {
                text = ', ' + text;
            }
        }
    }

    return text;
}

now = new Date();
foundationDate = new Date( 'March 1, 2010' );

dateA = new Array( now.getFullYear(), now.getMonth(), now.getDate() );
dateB = new Array( foundationDate.getFullYear(), foundationDate.getMonth(), foundationDate.getDate() );
dateC = diffDateTime( dateA, dateB );

document.write( 'Империя живёт уже <b>' + daysPassedText( dateC[0], dateC[1], dateC[2] ) + '</b>.' );
</script>