Monarch-
Acclimatised
When a crew member has spent 3 consecutive local nights on the ground within a time zone which is 2 hours wide, and is able to take uninterrupted nights sleep.
The crew member will remain acclimatised thereafter until a duty period finishes at a place where local time differs by more than 2 hours from that at the point of departure.
If you were doing a ULR out of Seattle (after having spent 2 weeks there) - You would be acclimatised for a ULR duty ex Seattle.
If you have been on leave in Seattle for two weeks then come back to Dubai the night before your ULR ex Dubai, you are not Acclimatised in Dubai.
The second sentence in the definition refers to where you leave Dubai - Acclimatised then go to say- Incheon, then after blocks on at Incheon - you are now no longer not acclimatised.
I'm afraid to say that you have been illegal operating a ULR after leave within 12 hours of getting back to Dubai.