Behind the scenes, Excel stores dates as serial numbers. This means that you can take a cell with the number 1 in it, format it as a date, and you’ll get January 1, 1900. So generally if you get a spreadsheet with dates in it and you see numbers in the date column, you can just format the numbers as dates (in the Number section on the Home tab of the ribbon), and everything works just fine.

But occasionally you may get a spreadsheet with a number like 91480 in a column like Date of Birth. When you format this as a date you get June 17, 2150. Probably not the date of birth you’re looking for. That’s because 91480 refers to the date 9/14/80 – it has just had the slashes removed. There’s a quick way to change 91480 to 9/14/80. Learn more…

Submitted by: Nina Maldonado