"only"
I prefer flying KLM over Singapore Airlines because of the departure time, SG departs 11 am, so by the time I arrive its the time my body thinks its bedtime, yet with the time difference the day there just starts (landing between 6 and 7 am). KLM departs 9 pm, so watch a movie, have dinner, pop a sleeping pill and wake up 8 hours later for breakfast, and arrival is around 4 pm. So only a few hours to kill before bedtime.