Dates are stored as the number of milliseconds from the Epoch 1 January 1970
To get the current date & time:
var today = new Date();
To set a date:
var special = new Date(1941, 1, 14); //year, month (zero based!), day
Or even more precisely to the second:
var happy = new Date(1969, 10, 18, 11, 45, 23); //year, month (zero based!), day, hours, minutes, seconds
Date object methods
today.getTime(); // returns the number of milliseconds since 01.01.1970
today.getDay(); // returns 0 - 6 day of week, where 0 = Sunday
today.getDate(); // returns 1 - 31 day of month
today.getMonth(); // returns 0 - 11
today.getFullYear() // returns YYYY, not zero based
today.getHours(); // returns 0 - 23
Example:
var today = new Date(1969, 10, 18);
today.getDay() ; //returns 2, indicating Tuesday
today.setMonth(2) ; // sets the month to March
today.setFullYear(1980) ; // sets year to 1980
today.setDay(0); // sets day to Sunday
Comparing Dates
var date1 = new Date(1969, 10, 18);
var date2 = new Date(1969, 10, 18);
if ( date1 == date2) { //returns false, because they are not the same OBJECT
if ( date1.getTime() == date2.getTime()) { //returns true, because the .getTime() method returns the milliseconds