Hello, what formula could I use to set conditional formatting on a page that
has 24 hour time for the entries? For example, if the entry in A1 is 1900,
and the next entry is due at 2100, how can I get the spreadsheet to show a
warning if the entry is early? Or if it's more than 30 minutes late late?

I'm using XP Pro and Office 2003, and I'm a beginner, so please keep it
simple.