Excel：使用2列之间的条件计算平均时间（持续时间）

Question

Breaking my head over this, time to look for help :(

I have a sheet with raw data, as illustrated below.
I'd like to calculate the average duration per TestName (column A) between the 2 timestamps (B and C) in another sheet.

How can I do this in 1 formula?

Note 1: The correct answer is (done manually)
test1 = 26:41:23
test2 = 08:23:10

Note 2: 1 formula please, without adding extra columns to calculate the duration per each first
Note 3: I cannot change the format of the raw data
Note 4: ignore empty fields

Thank you!

Answer 1

Use a new Column D to calculate the difference between start and end date on each row:

=DATEVALUE(C2)+TIMEVALUE(C2) - (DATEVALUE(B2)+TIMEVALUE(B2))

Next calculate the average on test1 and test2

=AVERAGEIFS($D:$D, $A:$A, "test1")
=AVERAGEIFS($D:$D, $A:$A, "test2")

Note that I'm using a comma as separator, in some languages, other separators, like semicolon are needed to write the formulas properly.

Now format the view to display at least the days in addition to the time: "DD - hh:mm:ss". Going beyond 31 days is a bit difficult as the month will count up. If you don't like the formatting, go with the raw number format and extract the information through a bit of math. If it shows for example 1,5 it means one and a half days. I hope you can handle converting decimals to hours, minutes and seconds. MOD(ulo) and Rounddown are going to be your friends. :-)