tl;dr Tested using dice rolls, where perfectly ethical participants should report an average score of 3.5. Night people are also less ethical in the mornings (4.22), but not as unethical as morning people are at night (4.56). Depressingly, average participants are still a bit dishonest during their temporal 'comfort zones,' although the morning people (3.86) once again outdo the evening people (3.8).

I've never trusted morning people and now I have evidence to validate my bias, ha ha! /tongue in cheek