You can tell yourself you're going to catch up on your grading, because after all, you have five uninterrupted solitary hours at home in the evening.
You can tell yourself that you can also do the laundry whilst catching up on your grading.
You can tell yourself you've got time to do a little light editing of your manuscript. Also, that you can go get it printed and put it in the mail.
You can tell yourself that changing the linens on the bed is a ten minute job. Fifteen, tops.
But you can't make five uninterrupted solitary hours do all that. You just can't, no matter how many stories you tell yourself about "uninterrupted" and "solitary" and even "five."
That is all.