It is not a difficult concept really, decimal time. 0.1 hr = 6 minutes.
1.0 to 2.7 = 1.7 hr
1673 to 1684 = 1.1 hr
1692.55 to 1693.45 = 0.9 hrs (but I normally forget the last digit).
1.1 Tach hrs= 1hr 6 mins
You can always use a calculator.
But I log TO to LD in the aircraft logbooks, and I normally get this from my watch, or some other nifty timing device like the transponder or GPS. My logbooks (flying) I get from my watch normally, if I remember. If not I use as above.
Last edited by englishal; 30th August 2013 at 14:23.