In Google Sheets, you have to format the cells correctly to calculate time. If you know how to format the cells, you can easily add and subtract time in Google Sheets.

New to Google Sheets? This guide walks you through the basics of how to use Google Sheets, from creating a new sheet to entering and formatting data.

You can change the date & time format in Google Sheets & Excel Online using this guide. Use different date & time formats in spreadsheets.