They're apart from each other for a fortnight once they've all returned to the Shire. It's understandable; they've been away from their families for over a year, it's only natural that they spend some time getting used to life in the Shire again.
Then Merry wakes up one day to find a letter on the table by his bed. It's from Pippin, sent that morning and about half a page long, 'I'm coming to visit you tomorrow' underlined at the bottom just above his name and a splatter of what he guesses to be jam.
Merry considers getting up, to help clear some of the mess that has managed to accumulate in his room in the space of fourteen days, or check that they have enough jam tarts in the kitchen. It's past second breakfast and Merry should be getting up for food alone, but after so long sleeping on the ground he's enjoying the novelty of a soft bed with feather pillows.
Instead he turns over and tries to fall asleep again; letter still in his hand, hoping that when he wakes up it will be tomorrow already.