I would stay away trying to be super detailed about what you did in small time increments, unless required by customer. Nobody really cares about it, it is much better to say "Feature A development. 30hrs" than "Feature A research 15 mins, Emails 1hr. Rework screen A 4hrs... and so forth in long letter that looks like AWS bill.
I do track my time per project (usually break down to dev and admin category) but give out just half-day or maybe hour increments.