Lack of Time in Mario Galaxy

Juul's discusses at length the lapsing of time in the game (fictional time) and the time taking to to play the game (play time). Now the game I played this week is the wii game Super Mario Galaxy. This game shows a  relationship between the play time in reality and the fictional universe of Mario; in the game there is no real sense of time movement in the game (no day or night changing), and no set time frame in the game. Given this I would assume that the relationship is like the text states as 1:1, that the movement made by the player directly affected the time movement in the game. Now there is an instance in the game that could display a sense of time; during the game there are a series of optional cut-scenes that involve storytelling by the character Rosalina, as she ends each cut-scene she states "That's should be enough for today." This could imply that everything leading up to that cut-scene is a single day. But this is incoherent since one can go a long period of time between these cut-scenes, and as I said earlier these are optional so if I chose to not participate in these cut-scenes then would that mean the day never ends?