I have a large group of spreadsheets, all with multiple tabs and values, of which approximately 10% of the cells contain dates. Once a year I have to manually go through these sheets and add a year onto all of the dates. For example, a cell containing 01/07/1935 would be changed to 01/07/1936. This process currently takes a couple of days. Is there any way this can be done automatically, by running a function or something, so that the dates are found and updated for me? Or even something that just lists all the cells that contain dates so I don't have to trawl through hundreds of tabs manually looking for the cells that contain dates? Any help would be much appreciated.