How to do calculations with dates in Excel

From Microsoft Excel 365 Training Johannesburg

You have to enter your date in "Date Format" in order to use it in a formula.

Excel recognizes the following formats as dates: 28 Oct 2018, 28 October 2018, 28 Oct 18, 2018/10/28

If you have an apostrophe ' before your date, Excel would recognize it as a label, and not as a value that you can use in formulas. We are going to calculate how many days you are old in cell C4 (DOB = Date Of Birth).

Row Colunm A Column B Colomn C

1 Start date End Date No of days

2 30-Oct-18 31-Oct-18 =B2-A2

3 30-Oct-18 02-Nov-17 =B3-A3

4 own DOB Date today =B3-A3

From Advanced Excel for the Power User