Set a revision point in Google Spreadsheets; or compare revisions between two arbitrary dates

Question

Google Spreadheets's Revision History is very handy. But, I often do things like:

1. Copy a Tab
2. Edit it
3. When finished, copy it over the original.

I want to see only the changes made in step 2. But I have to choose between "less detailed revisions" which shows me changes 1 and 2 combined or I get hundreds of Revisions (over, say a 3 hour period).

I'd like to be able to set "revision points" at times I know I'm making significant changes.

Answer 1

At this time is not possible to set "revision points". Instead, try the following:

1. Create a Copy of the spreadsheet
2. Edit it
3. When finished, copy it over the original

References
See the history of changes made to a file - Docs editors Help