计算时间差和总持续时间

Question

I am trying to create a small "app" using tasker on my android phone that am supposed to track my workhours and over/under-time. I have managed to get tasker to send timestamps on the start/end of each workday and are writing them to a google sheet so it gets recorded like:

                                     <Not implemented>        <Not implemented>  
 |     A      |       B     |    C     |     D     |    E       |    F    |
 | 2020-01-29 |     07:24   |   16:33  |    00:09  |            | -02:51  | 
 | 2020-01-30 |     07:00   |   12:00  |   -03:00  |            |         |

Where the "D" column is the difference between ordinary workhours (8) and actually registred hours.

The "F" column should summarize the "D" column and show the sum of all values. The data in the three first columns are beeing sent correctly but I cant figure out how to set up formulas so that the values for the "D" column is added and and same thing with the cell in the "F" column. I have been trying to change to different formats and tried creating my own formats to but do not understand how to get it to work.

Answer 1

I'm getting a different result than you in D1. I wonder if you're also accounting for a lunch hour (so subtract 9 instead of 8), but these formulas worked for me:

• in Column D: =(C1-B1)-(8/24)
• in Cell F1: =sum(D1:D2)

Column D and Cell F1 are formatted as Time > Duration.

Here's the result: