We are logging time by means off the hobbs timer in my FTO.
The hobbs timer start counting from engine start till engine stop ( detects oil pressure), engine start is maybe 1 or 2 min before we start taxi, so ist kind like block hours.
The hobbs timers works in ticks of 6 min, sometimes 10 sec after engine start it does the first tick and i have 6 min "flown" on the other hand, some times you can be 5 min and 50 sec in the "tick" at engine stop ant dont have the full 6 min's , so the 5min 50 sec will not be logged in the book.
In avarage this will cancel each other more or less. Sometimes i have 6 min " extra" sometimes not
