Node.js fsPromises.utimes() Method

The fsPromises.utimes() method is used to asynchronously change the modification and access timestamps of a file. The timestamps can be specified using a number, string, or Date object. An error would be thrown if the timestamp cannot be converted to a proper number, or is NaN, Infinity or -Infinity.

It changes the file system timestamps of the object referenced by path then resolves the Promise with no arguments upon success.

Syntax:

fsPromises.utimes( path, atime, mtime )

Parameters: This method accepts three parameters as mentioned above and described below:

• path: It is a string that denotes the path of the file whose timestamps have to be changed.
• atime: It is number, string or Date object that denotes the new access timestamp to be set.
• mtime: It is number, string or Date object that denotes the new modification timestamp to be set.

The atime and mtime arguments follow these rules:

1. Values can be either number representing Unix epoch time, Dates, or a numeric string like ‘123456789.0’.
2. If the value can not be converted to a number, or is NaN, Infinity or -Infinity, an Error will be thrown.

Example: This example to illustrate the fsPromises.utimes() method in Node.js. Create a example_gfg.txt file for input.

Filename: index.js

// Node.js program to demonstrate the
// fsPromises.utimes() method

// Import the filesystem module
const fs = require('fs');
const fsPromises = require('fs').promises;

console.log("Details before changing time:");

// Get the stats object of the file
prevStats = fs.statSync("example_gfg.txt");

// Access the modified and access time of the file
console.log("Modification Time:", prevStats.mtime);
console.log("Access Time:", prevStats.atime);

// Get the current time to change the timestamps
let newModifiedTime = new Date();
let newAccessTime = new Date();

// Use the utimes() function to assign
// the new timestamps
fsPromises.utimes("example_file.txt",
        newAccessTime, newModifiedTime);

// Get the stats object of the file
console.log("\nDetails after changing time:");

// Get the stats object of the file
changedStats = fs.statSync("example_gfg.txt");

// Access the changed modified and
// access time of the file
console.log("Changed Modification Time:",
                changedStats.mtime);

console.log("Changed Access Time:",
                changedStats.atime);

Step to run this program: Run index.js file using the following command:

node index.js

Output:

Details before changing time:
Modification Time: 2020-06-11T17:25:51.136Z
Access Time: 2020-06-11T16:50:51.223Z

Details after changing time:
Changed Modification Time: 2020-06-11T17:25:51.136Z
Changed Access Time: 2020-06-11T16:50:51.223Z

Reference: https://nodejs.org/api/fs.html#fs_fspromises_utimes_path_atime_mtime