# Is there a way to clear all the CellChangeTimes lists in a notebook?

I have a very large notebook that has evolved over years. It is the result of countless copy and paste, edit, divide, merge, etc., operations. Some of the cells have hundreds (thousands?) of elements in the CellChangeTimes list.

Is there a way to clear those? That is, without editing each cell by hand.

• You can try the "Clear history" button described here – Jason B. Apr 26 '18 at 21:33
• It took a while to open the dialog, but it worked. If you turn your comment into an answer, I will be happy to accept it. – Steven Thomas Hatton Apr 26 '18 at 21:43
• Years ago I had the same problem with a notebook of a customer and it was really slow to open.Since then I always switch off history tracking globally. This actually should be the default setting in Mathematica always. But I doubt WRI will change that... – Rolf Mertig Apr 27 '18 at 7:18

(Posting comment by Jason B. as an answer.)

You can use the "Clear history" button described here.

For a programmatic approach, this should work:

CurrentValue[Cells[], CellChangeTimes] = Inherited;


Then you may want to stop them being created:

CurrentValue[EvaluationNotebook[], "TrackCellChangeTimes"] = False;