Can we push this to next week? — Can we move the meeting to a later date?
Something came up. — A more pressing matter needs my time. No details are expected.
I need to bump our call. — I have to move our call.
Does Thursday work instead? — The new date is offered together with the cancellation.
Sorry for the late notice. — The apology is for the short notice, not for the change.
No worries! — The usual answer. No offense was taken.