I used vba to import a tab delimited text file.
I need to automatically do calcs on the data.
My A column has data in variable lengths in the following format
(beginning with Cell A22):

[Step 1]
time
12:00
12:02
12:04
12:06

[Step 2]
time
13:00
13:02
13:04
13:06
13:08

[Step X] Variable amount of steps and data
time
13:00
13:02
13:04
13:06


I want to put in a column the elapsed time for the data in each step,
restarting the time elapsed at 0 for each step.
So the first value would have 0. So in K24 I would have 0, in K25 I
would have A25-$A$24.
I am not sure how to loop and test to see if I need to start over
again with the next [Step]
I assume I need to anchor the first time reading after the word "time"
then use that to subtract from each other value untile a blank row is
found. Then start over.