Time Travel от Christian Pulvermacher

Usage:
- Open the tab you want to change the time in.
- Click the Extensions icon in the toolbar, then click Time Travel.
- Choose a date from the calendar and edit the time if necessary, or enter a date and time directly (see examples below).
- Confirm with Enter or by clicking the "Change Date" button.
- Any JavaScript Date or Intl.DateTimeFormat in the current tab now returns the fake date/time you set. Other tabs and origins are not affected.

To restore the system time, click the extension icon and switch off the "Enable Fake Date" toggle.

When the fake date is enabled, the clock runs forward from the configured time.
You can stop the clock by switching on the "Stop Clock" toggle. The fake date will be reset to the last value you set.

Example Dates and Formats:
- 2025-04-27 12:40 - Local time
- 2025-04-27 - Midnight UTC
- 2025-03-30 00:59:55 - Assuming your system timezone is Europe/London (GMT), 5 seconds before a one-hour jump to 2 a.m. (summer time)
- 2025-04-27T12:40Z - Set local equivalent for given UTC time
- 2025-04-27T12:40+1130 - Set local equivalent for time with +11:30 timezone offset. Note that actual time zone is not changed
- 2025-03-25T12:40:00.120 - Local time with milliseconds
- 1731493140025 - UNIX timestamp

Features:
- Fakes date and time for all methods of Date and Intl.DateTimeFormat objects.
- Time can be stopped and resumed.
- Option to automatically reload page after changing date.
- Only affects current tab after clicking the extension icon.

Limitations:
- Only JavaScript is affected by the extension.
- Some functionality or animations may behave strangely if the clock is stopped.
- The extension does not work in iframes with the sandbox attribute.

Contributions:
Contributions are welcome! If you have ideas, bug reports, or want to help improve Time Travel, please open an issue or submit a pull request on GitHub.