The 100hr EK roster also includes bunk time. As EK pays/credits the whole trip on the published roster. The bunk time does not count towards the 900hrs in 365days nor the 100hrs in 28 days. Meaning more than 9months flying at 100hrs can happen.
PS. Staying on local time is near impossible even at DXB due to so many departures leaving between 10pm and 6am. So although I fully endorse the ways of fighting jet-lag discussed above, the realist in me says if ya haven't done it, you don't know.