var theseMonths = new Array('January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December');
var theseMonthDays = new Array(31,28,31,30,31,30,31,31,30,31,30,31);
var today = new Date();
var thisYear = today.getYear();
var thisMonth = today.getMonth();
var nextMonth = thisMonth+1;
var thisMidMonth = 15;
var thisQuarterMonth = 7;
var thisThreeQuarterMonth = 21;

if (thisYear < 1000) thisYear +=1900;

var theseDays = theseMonthDays[thisMonth];

if (thisMonth == 1) {
    if (thisYear%400==0 || (thisYear%4 == 0 && thisYear%100!=0) ) theseDays +=1;
}

thisMonth = theseMonths[thisMonth];
nextMonth = theseMonths[nextMonth];