FormulaCamp
Completed
4. Excel Functions · Dates and Time · 15 min

21. Dates Are Numbers

Lesson 21 of 25
Task 1 of 4
  1. In D2:D5, calculate how many days each order was in transit.

Lesson theory

To Excel, a date is a day number counted from 1/1/1900. March 15, 2026 is day 46,096. That is why you can subtract and add dates:

=C2-B2 is the number of days between two dates; =B2+30 is the date 30 days later.
  • DATE(year, month, day) builds a date from numbers;
  • YEAR, MONTH, DAY split a date into parts;
  • TODAY() is today's date (it changes every day).

Type dates with slashes: 3/15/2026.

Practice is part of Pro

The live spreadsheet, task checking and .xlsx files in all 170 lessons. Your progress is saved in this browser; sync across devices is coming soon.