^^ Cannot change what? Why the speed at which yesterday passes. Because that is what Kirk asked him to change. Sorry Kirk, old boy, 50 fps is all I can do when showing the flow of history.
They never ask the Guardian if it can send them back to a specific date. And TBH, the Guardian is pretty useless as a time portal if it can't
My point exactly. Spock asks for a different action. As I said twice before, Kirk asks for a playback of history. Spock asks for access to a specific date. Spock has to jump through not knowing whether he'll get there in the morning or at night, but he'll get there on that date. Kirk just wanted to watch the show.