Given a date and the task is to subtract days from the date using JavaScript. To subtract days from date, some methods are used which are described below:
JavaScript getDate() Method: This method returns the day of the month (from 1 to 31) for the defined date.
Syntax:
Date.getDate()
Parameters: This method does not accept any parameters.
Return value: It returns a number from 1 to 31, representing the day of the month.
JavaScript setDate() Method: This method sets the day of month-to-date object.
Syntax:
Date.setDate(day)
Parameters:
- day: It is required parameter. It specifies the integer representing the day of the month. Values expected values are 1-31, but other values are also allowed.
- 0 will result in the last day of the previous month.
- -1 will result in the day before the last day of the previous month.
- If the month has 31 days, 32 will result in the first day of the next month.
- If the month has 30 days, 32 will result in the second day of the next month.
Return value: This method return the number of milliseconds between the date object and midnight of 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()
Parameters: This method does not accept any parameters.
Return value: It returns a number, representing the number of milliseconds since midnight on January 1, 1970.
JavaScript setTime() Method: This method sets the date and time by adding/subtracting a defined number of milliseconds to/from midnight January 1, 1970.
Syntax:
Date.setTime(millisec)
Parameters:
- millisec: It is required parameter. It specifies the number of milliseconds to be added/subtracted, midnight January 1, 1970.
Return value: It represents the number of milliseconds between the date object and midnight January 1, 1970
Example 1: This example subtract 4 days from the variable today by using setTime() and getTime() methods.
Javascript
let today = new Date();console.log("Today's date = " + today);Date.prototype.subtractDays = function (d) { this.setTime(this.getTime() - (d * 24 * 60 * 60 * 1000)); return this;}let a = new Date();a.subtractDays(4);console.log(a); |
Output:
Today's date = Tue Jun 13 2023 22:38:28 GMT+0530 (India Standard Time) Date Fri Jun 09 2023 22:38:28 GMT+0530 (India Standard Time)
Example 2: This example subtract 365 days from the variable today by using setDate() and getDate() methods.
Javascript
let today = new Date();console.log("Today's date = " + today);Date.prototype.subtractDays = function (d) { this.setDate(this.getDate() - d); return this;}let a = new Date();a.subtractDays(365);console.log(a); |
Output:
Today's date = Tue Jun 13 2023 22:41:00 GMT+0530 (India Standard Time) Date Mon Jun 13 2022 22:41:00 GMT+0530 (India Standard Time)
