
Time Travel by Christian Pulvermacher
Available on Firefox for Android™Available on Firefox for Android™
Fake the current date and time in JavaScript Date or Intl.DateTimeFormat objects. Time Travel helps you debug time-dependent frontend applications without having to change the system time.
You'll need Firefox to use this extension
Extension Metadata
Screenshots



About this extension
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
- Any JavaScript
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:
-
-
-
-
-
-
-
Features:
- Fakes date and time for all methods of
- Time can be stopped and resumed.
- 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
- 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 timestampFeatures:
- Fakes date and time for all methods of
Date
and Intl.DateTimeFormat
objects.- Time can be stopped and resumed.
- 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.Rate your experience
PermissionsLearn more
This add-on needs to:
- Access your data for all websites
More information
- Add-on Links
- Version
- 2.1.0
- Size
- 78.94 KB
- Last updated
- 21 days ago (Apr 2, 2025)
- Related Categories
- License
- MIT License
- Version History
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