Perhaps if I'd called ahead, you might have been able to fit me into your schedule.

"I fit it into my schedule once in a while."

But he could not fit the assignment into his schedule.

Please let me know if we can fit this into your schedule.

"I'm not sure that fits into my schedule right now."

Until then, we cannot fit it into our schedule.

If it doesn't fit into their schedule, suddenly half the year has gone by and you haven't had an assembly.

"I could fit you into her schedule in about two weeks."

"But I have to be able to fit it into my schedule."

It's so nice that you can fit me into your busy schedule.