Yes, you must enter your score between 7PM the day of and midnight the next day for each day of game play. That gives you 29 hours to enter your score for each day.
We recommend entering your score each day, as soon after 7pm if possible, so that your activities, experiences, and day's thoughts are still fresh in your mind. Your reflections about your day will be more meaningful if they come from contemporaneous thoughts rather than recollections later on.
If you miss a day of scoring, you can use a mulligan to reopen that day's scoring after the regular window has closed, but you still need to enter your true score. A mulligan does not give you any points, only the ability to enter the points you've earned after the scoring window closes.