>>96722791>i can't tell how much time has passed between the battle of mewnie and Marco going home, and then him coming back>Bon Bon the Birthday ClownMarco and Jackie start dating
>StarcrushedThe end of the school year
Star leaves Earth
>Marco and the KingMarco leaves Earth a few days later
>Scent of a HoodieMarco goes back to Earth; he had been staying on Mewni with Star for some time, but must have gone back at least once, since has a bag full of stuff he didn't bring with him the first time.
>Sophomore SlumpMarco says its almost his and Jackie's three month anniversary; about three months have passed since Bon Bon the Birthday Clown.
Jackie comments that about half that time was "long-distance" (ie; Marco was on Mewni). Between "Marco and the King" and "Scent of a Hoodie," about six weeks passed.
The episode ends with Marco being sent off back to Mewni at the start of the new school year. Assuming Echo Creek has a standard June to September summer vacation, this means another month or so passed between Marco and Jackie breaking up and Marco deciding to actually go back to Mewni.
During this time Marco did not think to actually tell Star he was coming, and Star did not contact him because she was trying to get over her feelings for him and keeping herself busy with her princess duties, as we saw in the episodes between "Scent of a Hoodie" and "Sophomore Slump."
This also means Star and Marco should be 15, since they were 14 at the start of the last school year.
The show could have done a better job at conveying how much time has passed, with a short scene in between these episodes like having Star mention how long it's been since she saw Marco and wanting to call him but holding herself back because she told herself she'd get over him, but ultimately they did tell us enough to piece it together, and in a way making it just as jarring for us as it was for Marco makes us feel for him a little more.