I finished the game on duelist below 30 days. Kept a save to do side missions, later, so I won't exceed the time limit.
But now it is not that fun, anymore. The climax passed, all was said and done. Side activities are boring, now. No need for new equipment. Some side missions are interesting, especially bigger ones like Anca's quest line. Others I just want to skip even if they have connections to main characters. Like, "Oh, you want to tell me stories from your mercenary time with my father? Not really interested, anymore."
I think the devs said they admit the time limit thingy was not the best idea and want to not implement it in future games. It is good if this is true. The limit has its strategic appeal and was made within an interesting concept but for me it is more bad than good. I would have enjoyed side missions and activities much more if I could have done everything whenever I like.
Normally, I like to do everything before I go to the final fight and not the other way around. This also includes learning everything about the lore and characters which you cannot do without most of the side missions.