Date and Time in JavaScript

The date object is very useful for obtaining the date and time on the client. It supports various methods, which return a specific value.

To start working with dates and time, we first initialize a variable and assign it a value with the new operator and the Date() constructor. The main function of the new operator with Date() constructor is to create a new date object that is stored in the variable. Here is the code:

   var d = new Date();

Thus, variable d contains a new date object. We can now call the various methods of this date object.

var t_date = d.getDate();      // Returns the day of the month
var t_mon = d.getMonth();      // Returns the month as a digit
var t_year = d.getFullYear();  // Returns 4 digit year
var t_hour = d.getHours();     // Returns hours
var t_min = d.getMinutes();    // Returns minutes
var t_sec = d.getSeconds();    // Returns seocnds
var t_mil = d.getMilliseconds;  // Returns Milliseconds

Now we can easily display the date, month and year in an alert box, using the values stored in respective variables.

alert("Today's date is " + t_date + "-" + t_mon + "-" + t_year);

Click here to display the alert box

The eagle-eyed would have noticed that the month digit is one less than the present month. Hence, if you want to display the month, increment the value returned by getMonth() by 1. The corrected code should be:

t_mon++;
alert("Today's date is " + t_date + "-" + t_mon + "-" + t_year);

Check the results

Similarly, we can get the time using the variables that store hours, minutes, seconds and milliseconds values.

alert("The time is " + t_hour + ":" + t_min + ":" + t_sec);

Get time in an alert box

In the next session we'll see how we can display a greeting based on the client time.

1. Which method of the date object is used to get four digit year value?
2. What is the value of variable mon assuming that the present month is March?

      var t = new Date();
      var mon = t.getMonth();
   

3. The hours are represented in 24 hour clock. If midnight is 0 what is noon?