TDBAdvGrid before post

Hi, i need to change the value of the editor before save in DB (for example edit is a time and i need to save as float or edit is a combolist and need save the index instead of string)
Which event should I use?

Did you try grid.OnCellValidate() where you can change the var parameter Value?

Yes thanks it did the trick.
Now, however, in a column if I enable the edTime editor and, after clicking on the cell, I press the "esc" key I get the error
"Exception class EConvertError with message ''' is not a valid time'."
What can I do?

I would expect this is an exception caught by the IDE. When you run the app in release mode outside the IDE, you should not see this exception.
All gracefully handled exceptions in the app are always shown when run from the IDE but should not harm when running outside the IDE.