Board Thread:Questions and Answers/@comment-30771283-20171113094245/@comment-1327106-20171113174237

That depends on how much and how often you play. I think it took me about three months before I stopped playing the game, but I didn't play everyday and most of it wasn't even unlocking the epilogue missions. I was also trying to do all the base quests and S-rank all the missions (you get some cut scenes for finishing quest chains), so I ended up replaying a lot for other reasons.

I don't remember how long it takes to go through individual missions, but let's say you do 3 missions a day. It'll take you around two and a half weeks, maybe less, to unlock all the epilogue missions from scratch. If you do through more missions in a play session, you'll unlock faster.

The main game itself (the Ch1-3 content) goes by a lot faster, lasting a weekend to a week depending on how fast you are. The only way to stretch it to a month is to do the extra Survey Missions, quests, and epilogue.