Excel 2010 sometimes opens with formulas or number entries changed to dates in many columns throughout workbook. But not all columns.
The "number format" automatically changes from
DATE. This effects dozens of columns. It does not happen during use while excel is open. It only occurs after the document is closed and reopened. It has occurred about 4 times in the past 2 years. But if it was not for my backups, this would be a mess.
It has happened with different files.
The file effected today has 22 sheets with 15 sheets effected. The effected cells are manifested with hash marks because the dates are too long to fit into the narrow cell.
I am inspecting the damaged file and just realized that ALL sheets have ALL cells converted to DATE number format! That ought to simplify the diagnosis?
Finally, is there a simple way to reversing this problem other than opening an older version of the file?