[Dropped] Message: Wrong date format

[Benny1]

I have been using this spreadsheet all of 2024 and now it is not letting me use a day after 01/01/2025. I get an error message that says
Wrong Date Format!
Please print the date in the following format: 00/00/0000 (Eg: 1/1/2020

Last input date 12/31/2025

How can I get this spreadsheet to take the date 01/13/2025 for example

[FJCC]

If I enter either 01/13/2025 or 1/13 in a cell, I get a date displayed as 01/13/25, as expected for my US locale.
Can you upload a file that has this problem and explain which cell you are trying to enter a date into?
To upload a file, click Post Reply and look for the Attachments tab just below the box where you type a response.

[Benny1]

Here is the screenshot

[RoryOF]

A screenshot is little use for diagnosis, as we can only see what is being shown, not what is causing the problem.

[Lupp]

Anyway "00/00/0000" isn't an acceptable format for any value represented by a number in a spreadsheet.

If somebody insists on one of the slashed formats DD/MM/YYYY (UK and many countries) or MM/DD/YYYY (hopefully only USA) or on an abbreviated format with 2-digit year does it on their own risk, because these "formats" are ambiguous and cause misundertstandings again and again.

Use YYYY-MM-DD, and get the lot of advantages of this globally standardized format (ISO 8601).

[robleyd]

With cursor in that cell, choose Data | Validity and see if you get a dialog box with validity settings.