Change default date format in Excel for Mac

Thanks for the prompt response.

I had already done everything you suggested, and all of my apps and my Mac are the most recent versions. I even restarted my computer. It still doesn't work.

Below are the screenshots you requested. I hope you can help.

Dear jilliangran

Good day! Thank you for posting to Microsoft Community. We are happy to help you.

1. Based on your description, we did a test on our end, go to System Preferences --> Language and Region --> Advanced --> Dates, and

it shows four types of date format as the screenshot below:

If you want to set Excel to default to a date format of 1/1/22, you can Type in or click and drag elements to format your "Short" date

2. If you set the correct steps but the date format still can't work, please make sure your Excel and your Mac have updated to the latest version, sometimes, the update will also caused unexpected behavior.

• For Excel: Click Excel icon> Help> Check for Updates>Click Update to download and install all the available updates.
• For Mac: the latest update version for macOS Monterey is version 12.4, see Update macOS on Mac - Apple Support

3. Besides, since the default formats used by Excel for Dates, Times & Numbers is determined by the macOS System Preferences for Language & Region. You must restart the program in order for the changes to go into effect after you set this in Date page. Here is a similiar thread, you can have a reference: How do I change the default date format on Excel for Mac to - Microsoft Community
4. Meanwhile, we would like to collect more detailed information about the situation you are experiencing so that we can have further investigation:

1. Can you give us a screenshot that your full Date page to us like the pictute below?

2. Please also give us a screenshot of your Excel and Mac version.

• For Excel: click Excel>About Excel
• For Mac: Click the Apple icon>Abot the Mac

We’re looking forward to your reply and will continue to help you all the time!  If there are any misunderstanding or unclear, You can post back in your free time.

Sincerely,

Stacey | Microsoft Community Moderator

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Dear jilliangran

Thank you for your quick response and we also appreciate that you spent your precious time doing these tests and provided the detailed information to us. And sorry for the late reply due to the weekend.

If you the date format still can't work well in your end by the above methods, please try to use safe mode to check if other programs or startups caused this situation, for your reference: How to use safe mode on your Mac - Apple Support

***Disclaimer:***Microsoft provides no assurances and/or warranties, implied or otherwise, and is not responsible for the information you receive from the third-party linked sites, or any support related to technology.)

Meanwhile, to narrow down if the behavior was related to your local environment, try to change the date format in Excel via another device to check the behavior.

Create a new user profile on your Mac then sign in and use Excel to check if the same behavior will happen again.

Besides, may I know does your other colleagues have the same behavior when use the date format function in Excel?

We're waiting for your reply and will continue to help you all the time!

Your understanding and patience will be highly appreciated! Hope you have a good day.

Sincerely,

Stacey | Microsoft Community Moderator