How to Set Date Time from Mac Command Line

By  on  

Working on a web extension that ships to an app store and isn't immediately modifiable, like a website, can be difficult. Since you cannot immediately deploy updates, you sometimes need to bake in hardcoded date-based logic. Testing future dates can be difficult if you don't know how to quickly change the date on your local machine.

To change the current date on your Mac, execute the following from command line:

# Date Format:  MMDDYYYY
sudo date -I 06142024

This command does not modify time, only the current date. Using the same command to reset to current date is easy as well!

Recent Features

  • By
    An Interview with Eric Meyer

    Your early CSS books were instrumental in pushing my love for front end technologies. What was it about CSS that you fell in love with and drove you to write about it? At first blush, it was the simplicity of it as compared to the table-and-spacer...

  • By
    CSS Gradients

    With CSS border-radius, I showed you how CSS can bridge the gap between design and development by adding rounded corners to elements.  CSS gradients are another step in that direction.  Now that CSS gradients are supported in Internet Explorer 8+, Firefox, Safari, and Chrome...

Incredible Demos

  • By
    pointer Media Query

    As more devices emerge and differences in device interaction are implemented, the more important good CSS code will become.  In order to write good CSS, we need some indicator about device capabilities.  We've used CSS media queries thus far, with checks for max-width and pixel ratios.

  • By
    Submit Button Enabling

    "Enabling" you ask? Yes. We all know how to disable the submit upon form submission and the reasons for doing so, but what about re-enabling the submit button after an allotted amount of time. After all, what if the user presses the "stop"...

Discussion

  1. Richard

    I didn’t understand your exact use case, but a helpful way to do date-related testing without modifying your actual computer date/time, is to shim the system calls with library pre-loading. On a Mac, dyld can do this with DYLD_LIBRARY_PATH. On Linux, GNU ld can do it with LD_LIBRARY_PATH.

    This makes it easy to write tests for specific situations, such as monthly changeovers, leap-occurrences, timezones, etc.

    “libfaketime” is a handy library written for this, https://github.com/wolfcw/libfaketime. It’s even packaged in homebrew, just do brew install libfaketime. :)

Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!