JavaScript | Adding days in milliseconds to Date object

Given a date, the task is to add days in milliseconds to it. To add days in milliseconds to date object in JavaScript, some methods are used which are listed below:

  • JavaScript getMilliseconds() Method: This method returns the milliseconds (from 0 to 999) of the provided date and time.

    Syntax:

    Date.getMilliseconds()
    

    Return value: It returns a number, from 0 to 009, representing the milliseconds.

  • JavaScript setMilliseconds() Method: This method sets the milliseconds of a date object.
    Syntax:

    Date.setMilliseconds(millisec)
    

    Parameters: It accepts single parameter millisec which is required. It specifies the integer value representing the milliseconds. The expected values are 0-999, but other values are allowed.



    Note: The parameter accepts values apart from their range and these values works like:

    • millisec = -1, it means the last millisecond of the previous second and same for the other parameters.
    • If millisec passed as 1000, it means the first millisecond of the next second and same for the other parameters.

    Return value: It returns a number, denoting the number of milliseconds between the date object and midnight January 1 1970.

  • JavaScript getTime() method: This method returns the number of milliseconds between midnight of January 1, 1970, and the specified date.

    Syntax:

    Date.getTime()

    Return value: It returns a number, representing the number of milliseconds since midnight January 1, 1970.

  • JavaScript setTime() method: This method sets the date and time by adding/subtracting a defines number of milliseconds to/from midnight January 1, 1970.

    Syntax:

    Date.setTime(millisec)

    Parameters: It accepts single parameter millisec which is required. It specifies the number of milliseconds to be added/subtracted, in midnight January 1, 1970

    Return value: It returns the number of milliseconds between the date object and midnight January 1 1970.