I think cause there are seasons for free for all and 2v2 and the leaderboards and stuff get reset after the season ends so that number of days left is how long till the season ends. Chea!
No no not at all your online pass is good for as long as you have the game. the whole season thing just has to do with stats and leaderboards. You will be able to play online forever pretty much if that is what you were wondering.
So I can only play online for so long before I need a new pass?
no no no! You notice how the titles are unlocked by "completeing _ season/s with _ belt"? well when the season ends, you get your rewards for however you placed, along with recognition for your placing. then aother season starts back up and everyone is at no belt again and have to work their way up