Hi
Your dates are probably text looking like dates, not real dates.
One way to change this would be to select the range with dates, go to Data -Text to columns - Next - Next and change the Date format to DMY - Then finish
If it does not work, try other variations in the dropdown box.
Then refresh your data

__________________
Using O365 v2503 - Did you know you can thank someone who helped you? Click on the tiny scale in the right upper hand corner of your helper's post