How to Subtract Days from a Plain Date?

When working with dates in JavaScript, there may be times when you need to subtract a certain number of days from a given date. This can be useful in various scenarios, such as calculating a past date or determining a deadline.

Fortunately, JavaScript provides several ways to subtract days from a plain Date object. Let’s explore a few of these methods:

Method 1: Using the setDate() Method

The setDate() method allows you to set the day of the month for a given date. By subtracting the desired number of days from the current day, you can effectively subtract days from the date.

const date = new Date();
const daysToSubtract = 7;

date.setDate(date.getDate() - daysToSubtract);

console.log(date);

This code snippet creates a new Date object and subtracts 7 days from the current date using the setDate() method. The resulting date is then logged to the console.

Method 2: Using the getTime() Method

The getTime() method returns the number of milliseconds since January 1, 1970, for a given date. By subtracting the desired number of days in milliseconds and creating a new Date object, you can achieve the same result.

const date = new Date();
const daysToSubtract = 7;
const millisecondsPerDay = 24 * 60 * 60 * 1000;

const newDate = new Date(date.getTime() - daysToSubtract * millisecondsPerDay);

console.log(newDate);

In this example, we calculate the number of milliseconds per day and multiply it by the number of days to subtract. We then subtract this value from the current date’s timestamp using the getTime() method. Finally, we create a new Date object with the updated timestamp and log it to the console.

Method 3: Using the Moment.js Library

If you prefer a more comprehensive solution, you can use the popular Moment.js library. Moment.js provides a range of powerful date manipulation functions, including subtracting days from a date.

First, you need to install Moment.js by including the following script tag in your HTML:

Once Moment.js is included, you can use the subtract() method to subtract days from a date:

const date = moment();
const daysToSubtract = 7;

const newDate = date.subtract(daysToSubtract, 'days');

console.log(newDate);

This code snippet uses Moment.js to create a new moment object representing the current date. We then use the subtract() method to subtract 7 days from the date. The resulting date is stored in the newDate variable and logged to the console.

These are just a few ways to subtract days from a plain Date object in JavaScript. Depending on your specific use case and preferences, you can choose the method that best suits your needs.