Currently it says "1 Days" in the game but most things in the game count down in smaller increments so if it says "1 minute" it can be anywhere from 60 to 119 seconds but is actually always more than one minute in length.
Using that logic, "1 Day" could be anything from 24-47 hours or, if they depart from that format it could be the last 24 hours of the event.
Basing it on this, I'm not sure if I should be completing everything today or will have time tomorrow as well with an hourly countdown replacing the days countdown late tonight.
Is there text anywhere that says "Game ends on _____ date"?
The info panel for the event doesn't have a specific time/date end point that I could see, neither does the App Store blurb.