How to add fragment activity to activity?

How to make Excel automatically add up the time elapsed for every activity in a day/month?

• I have an Excel file wherein the start and stop time of every activity(computer boot up, work, break, meeting, computer log off) within a day/shift is listed down. This is done on the same worksheet every month. What I want to do is that on every instance a stop time is entered for a certain activity, the time elapsed for that activity is automatically added up to a cell (in another worksheet but still in the same file) dedicated for the total time spent for the specific activity (in a whole month). What function would be applicable to do what I want to achieve here?

• Answer:

  you will have to have another column in your primary worksheet that calculates the elapsed time, then is a simple matter to have a cell in another sheet sum all the entries in the primary sheet.