How to set to other time zone in Cypress?

Setting the timezone to other time zones in Cypress is a relatively simple process that can be achieved in multiple ways. Here are two commonly used methods:

Method 1: Using Environment Variables

Cypress allows you to change the timezone by setting environment variables. You can set the TZ environment variable before running tests. This approach is particularly effective on UNIX systems (including macOS). For example, if you want to set the timezone to New York time (Eastern Time, USA), you can do this in the command line:

bash
TZ=America/New_York npx cypress open

Or set a script in package.json:

json
"scripts": {
    "cypress:ny": "TZ=America/New_York npx cypress open"
}

Then you can run npm run cypress:ny to launch Cypress, at which point the timezone is set to New York time.

Method 2: Dynamically Setting in Test Code

Cypress also supports dynamically modifying the timezone during test execution. You can achieve this by modifying the Date object. For example, if you want to set the timezone to London time in a specific test, you can use the following code:

javascript
it('should handle London timezone', () => {
    const realDate = Date;
    class MockDate extends Date {
        constructor(...args) {
            super(...args);
            const date = new realDate(...args);
            const londonTime = date.getTime() + (date.getTimezoneOffset() * 60000) + (3600000 * 0);
            this.setTime(londonTime);
        }
    }
    global.Date = MockDate;

    // Here is your test code

    global.Date = realDate; // Restore original Date after test
});

This code simulates London timezone time by inheriting from the Date class and modifying its behavior. This method allows you to modify the timezone within specific tests without affecting the global environment setup.

Conclusion

Depending on your specific needs, you can choose to use environment variables to globally change the timezone, or dynamically modify the timezone within test code. The environment variables method is simple and easy to implement, suitable for scenarios where you need a unified timezone throughout the entire test. The dynamic timezone setting method provides higher flexibility, suitable for cases where you only need to change the timezone in specific tests.