We see a red flag when there is understaffing. We don’t have any flag for overstaffing. If you would like to edit these rules, it is easy.
In the Calendar sheet, select cell D7.
Click on Conditional Formatting menu and choose Manage Rules.
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Click on Edit Rule.
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We can see the rule used.
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You can change the icons used for the three options (+ve number, 0, -ve number).
After changing, Click OK in the dialog boxes and apply changes.