Excel’s SUM, DATE, WEEKDAY, IF, Nested IF, and IF/OR functions came to mind as I was watching a 1969 film called If It’s Tuesday, This Must Be Belgium, about American tourists on a whirlwind tour of ...

If you need to calculate dates in your spreadsheets, Excel uses its own unique system, which it calls Serial Numbers. Every date (month, day, year) and time (hour, minute, and second) has an ...