its up to you
As long as you know what it is you're tracking, that's all that is important. You want to be able to compare casino to casino, city to city, shift to shift, various game types, how it changes year to year, etc. As long as you are able to make sense of your records for comparison purposes in the future it is okay.
I start counting my time when I count my first card, whether I'm playing or backcounting. I end the time when I decide to terminate the session. I include table search time within the same casino if I am really looking for a new place to play. I don't include travel time from one casino to another. But this is just my way. Anyway you do it is okay.
The one thing I do think is important is including table search time if you do both play all and Wonging and wish to compare win rates. When only counting time actually at the table it distorts the difference to an amount much bigger than your actual win per hour of effort difference.