When planning an appointment for a specific day (and time), for example, should on or for preposition be used? See the context below, though, I am guessing, the rule should be universal:
Sure, I will tentatively pencil you in for Sunday evening.
Is there change in meaning if I use on above? I picked for simply because it sounds better -- and more intuitive.
"For" is more natural to my ear.
Also "on" would be potentially ambiguous, as it might have the meaning "When it gets to Saturday, I will pencil you in". Not a very likely reading, I admit, but there may be cases where the ambiguity is more likely.
The choice of preposition makes little difference. I would use "for", but "on" would also be technically correct.
The real meat of the sentence comes from the phrase "pencil you in" which refers to writing an engagement down on some kind of calendar or schedule, but doing so in pencil rather than pen which is less permanent and can be changed if the circumstances change.
The phrase, in my head, is short for "I will pencil you in for a meeting on Sunday". The words "a meeting on" are omitted as implied.
Using "on" changes the meaning of the phrase; "I will pencil you in on Sunday" implies that the speaker will actually put the entry in the appointment book on Sunday. Perhaps they're away from home and won't have access to their datebook until then. Perhaps they won't know whether there will be a conflict until then.
So, the use of "on" is valid, but results in a very different meaning than the one normally implied by the use of "for"; in that case, the speaker is saying they will tentatively add the appointment, which would occur on Sunday, to their book at some indeterminate but probably very near-term time.
