Well, this is not a annoying glitch, but has been happening a long time (over half a year, I believe). This symurgh (http://beastkeeper.com/pet/217058), always and only him, returns one hour earlier from his quests. The bug has occurred several times, including today, and I don't think any of his genes cause it.

I know I didn't send him earlier than the others pets; today I sent all them at  00:something, with the renewal of the quest board, so it couldn't have been  earlier.

As I said before, it is not a huge problem, but it kinda puzzles me.

Thank you

It's not a coding bug but a missing part of gene description. Sense of Direction reduces quest time by 1 hour. I updated its description. Sorry for the confusion.

Ah, that explains a lot! Thank you, Angel!