Much depends on what he is doing at that moment. Usually a maximum of 2-3 days. It happens that it takes longer if he is working on some very difficult stage.
There is only one recommendation, it is universal: ask the Bartender for advice, find out from the fortuneteller about how to increase the level of relationships with characters for whom personal quests are available.
Because the game is structured in such a way that you need to complete all the quests, even if you don’t like one or more characters.
These two characters (the bartender and the fortune teller) always help me complete the game 100%