Quite easily actually ...
So nice to see you on Pprune again Tudor! Even in this somewhat obscure forum (!?)
Sprogget is on the right track - First check for consistency in the date format (ie. make sure that there aren't any inconsistencies in the separators);
Then highlight the column containing the dates and then click Format => Cells; Select Custom (right down at the bottom) and enter yyyy/mm/dd, Click OK -- and that should do the trick ...
Feline Felicitations
Aaah! See you got there before me - but my way doesn't call for inserting a new column - more elegant?
Last edited by Feline; 19th April 2009 at 18:14.
Reason: See you lucked out before I posted