I never indicated you said such, reading the varying solution drew that conclusion. You stated using “decimal numbers” and thus, as I stated, using numeral value. Isn’t that the same with the addition of decimals? Also, I changed the format in one row to test it out and not being completely spreadsheet literate, I can’t figure out your meaning. If I change the two cells in rows to decimals, the total in column F is inaccurate. How can I replace 6:30 PM with a decimal and yet, display the time I started? I can’t replace with 6.5 PM to 11:15 PM in C3 or 11.25 PM. The total would be the sum of those two numbers equaling 17.75. If I just changed the format in column F to decimal from the added times in each rows, that doesn’t add either. Therefore, I’m stumped and decided just to deal with it manually. Replying in an “answer” box was simply my final answer to do it this way.
Have you really read and tested the suggested solutions? In case I will simply add them up manually and input into the cell. I’d also say “If this is your conclusion …” and would shake my head. No one suggested to create something like 6.5 PM in column B/C.
All you would have to do is to take the file provided by @anon73440385 in the first answer. There you have still your structure, there you have the correct formulars already in place, there you have the correct totals line-by-line and in column F. If you don’t like the numeric totals you could add another column G where you copy the result e.g. G3 =F3 and according the column down plus configure the format to [HH]:MM, voilà display style as you prefer. It’s also not necessary to understand the formula. Copy, paste & modify the formular would also suffice if you’d prefer to continue with your original file.
If you enter decimals the value isn’t a time value. A decimal value 6.5 does not equal time 6:30, 6.5 used in time calculations would be 6 days and 12 hours. Do not change the values in column B or C. Change the formulas in column F instead, as given in my answer. Read it, understand it, do it. Or do it without understanding, but don’t try to do something else without understanding.