I just input a date in what I thought was a column of date format cells and it went wrong. Now I see my original cells all have dates like 2/4/20 whereas now this cell at least will only accept four digits for the year like: 2/4/2020 and if I try to input something else it will change it to that.
So a first place for me to try understand what is wrong is to see what format those original cells are in. But I can’t see how to do that?
Can it be done?
Right click on a cell(s), select Format cells (or just Ctrl+1). In the dialogue box that opens select the tab Numbers, read the format of the cell as highlighted.
Make sure the language matches what you expect, in English (UK) 2/4/20 (DD/MM/YY) is 2nd April 2020 while in English (USA) 2/4/20 (MM/DD/YY) is 4th February 2022. Best to format all in ISO standard YYYY-MM-DD
If the cell is formatted as Text you will have problems, see How to convert number text to numeric data