When doing our result I put in the setting times and checking off times of every ETS clock,this is the only way to get a correct variation,ETS CLOCKS ARE NOT ALWAYS CORRECT at strike off, manual clocks are usually all set and checked off at the same time but if not their times are also put into the result programme individually.You cannot do it any other way to get a true flying time as the clock variation will be different if you start adding or taking away minutes to the setting and checking times,or even thinking that the ETS clock is correct at strike off.