JavaScript Date Object

Describes the JavaScript Date Object including properties, constructors, and methods.

Properties

• prototype - For creating more properties.

Constructors

• Date() - Use the current date and time to create an instance of the object date.
• Date(dateString) - Use the date specified by the string to create the instance of the date object. String format is "month day, year hours:minutes:seconds".
• Date(year, month, day) - Create an instance of date with the specified values. Year is 0 to 99.
• Date(year, month, day, hours, minutes, seconds) - Create an instance of date with the specified values.

Methods

• getDate() - Get the day of the month. It is returned as a value between 1 and 31.

  var curdate = new Date()
  var mday = curdate.getDate()
  document.write(mday + "<BR>")
  

  The above code prints the day of the month.

• getDay() - Get the day of the week as a value from 0 to 6

  var curdate = new Date()
  var wday = curdate.getDate()
  document.write(wday + "<BR>")
  

  The above code prints the day of the week.

• getHours() - The value returned is 0 through 23.

  var curdate = new Date()
  var hours = curdate.getHours()
  document.write(hours + "<BR>")
  

  The above code prints the hours since midnight.

• getMinutes() - The value returned is 0 through 59.

  var curdate = new Date()
  var minutes = curdate.getMinutes()
  document.write(minutes + "<BR>")
  

  The above code prints the minutes past the hour.

• getMonth() - Returns the month from the date object as a value from 0 through 11.

  var curdate = new Date()
  var month = curdate.getMonth()
  document.write(month + "<BR>")
  

  The above code prints the numeric value of the month.

• getSeconds() - The value returned is 0 through 59.

  var curdate = new Date()
  var seconds = curdate.getSeconds()
  document.write(seconds + "<BR>")
  

  The above code prints the seconds since the last minute.

• getTime() - The number of milliseconds since January 1, 1970. this function allows you to manipulate the date object based on a millisecond value then convert it back to the form you want. In the example below, it is used to set a future expiration time of a cookie.

  var futdate = new Date()
  var expdate = futdate.getTime()
  expdate += 3600*1000 //expires in 1 hour(milliseconds) 
  futdate.setTime(expdate)
  

• getTimeZoneOffset() - Time zone offset in hours which is the difference between GMT and local time.

  var curdate = new Date()
  var offset = curdate.getTimeZoneOffset()
  document.write(offset + "<BR>")
  

  The above code prints the number of hours different between your timezone and GMT. This value may change with daylight savings time..

• getYear() - Returns the numeric four digit value of the year.

  var curdate = new Date()
  var year = curdate.getYear()
  document.write(year + "<BR>")
  

  The above code prints the numeric value of the year which is currently 2000.

• parse() - The number of milliseconds after midnight January 1, 1970 till the given date espressed as a string in the example which is IETF format.

  var curdate = "Wed, 18 Oct 2000 13:00:00 EST"
  var dt = Date.parse(curdate)
  document.write(dt + "<BR>")
  

• setDate(value) - Set the day of the month in the date object as a value from 1 to 31.
• setHours(value) - Set the hours in the date object with a value of 0 through 59.
• setMinutes(value) - Set the minutes in the date object with a value of 0 through 59.
• setMonth(value) - Set the month in the date object as a value of 0 through 11.
• setSeconds(value) - Set the seconds in the date object with a value of 0 through 59.
• setTime(value) - Sets time on the basis of number of milliseconds since January 1, 1970. The below example sets the date object to one hour in the future.

  var futdate = new Date()
  var expdate = futdate.getTime()
  expdate += 3600*1000 //expires in 1 hour(milliseconds) 
  futdate.setTime(expdate)
  

• setYear(value) - Set the year in the date instance as a 4 digit numeric value.
• toGMTString() - Convert date to GMT format in a form similar to "Fri, 29 Sep 2000 06:23:54 GMT".

  var curdate = new Date()
  dstring = curdate.toGMTString()
  document.write(dstring + "<BR>" + curdate.toLocaleString() + "<BR>")
  

  The above example produces:

  Wed, 18 Oct 2000 18:08:11 UTC
  10/18/2000 14:08:11
  

• toLocaleString() - Convert date to local time zone format. See the example, above.
• UTC() - Based on a comma delimited string, the number of milliseconds after midnight January 1, 1970 GMT is returned. The syntax of the string is "year, month, day [, hrs] [, min] [, sec]". An example is "2000, 9, 29, 5, 43, 0" for Sept 29, 2000 at 5:43:0. The string is considered to be GMT. The hours, minutes, and seconds are optional.

  document.write(Date.UTC(2000, 9, 29, 5, 43, 0) + "
  ")
  

  The above example produces:

  972798180000