Why does 土曜日に予定があります sound off?


From this [answer](https://japanese.stackexchange.com/a/94023/45630),

> While totally acceptable in everyday conversation, the following polite
> versions still don’t quite sound natural to me as standalone sentences.
>

>> 土曜日に予定があります。

>>

>> 土曜日に予定がありません。

> That (今週末、予定はありますか) sounds natural. You could also say 今週末は（何か）予定がありますか. It
> is the に that is making the sentences above somewhat unnatural.

It figures looking at the search results:

  * [sentencesearch.neocities.org](https://sentencesearch.neocities.org/#%E4%BA%88%E5%AE%9A%E3%81%8C%E3%81%82%E3%82%8A%E3%81%BE%E3%81%99)
  * [jisho.org](https://jisho.org/search/%E4%BA%88%E5%AE%9A%E3%81%8C%E3%81%82%E3%82%8A%E3%81%BE%E3%81%99%20%23sentences)
  * weblio.jp | [予定がある](https://ejje.weblio.jp/sentence/content/%E4%BA%88%E5%AE%9A%E3%81%8C%E3%81%82%E3%82%8B) | [予定があります](https://ejje.weblio.jp/sentence/content/%E4%BA%88%E5%AE%9A%E3%81%8C%E3%81%82%E3%82%8A%E3%81%BE%E3%81%99) .

は is preferred over に, or sometimes no particle at all. However, に is used
quite often.

Assuming context is not important, then my guess is that, as あります is あり + ます,
あり is more along the lines of _to exist_ rather _to happen_. Similarly, we say
あり得る _possible to exist_ and 起こり得る _possible to happen_. Under this reasoning,
土曜日に予定があり is bad but 土曜日に予定があって fine.




I think the reason they sound a bit off as standalone sentences compared to,
say, 月曜日に試験があります is as follows. に as the time marker expects an event to be
bound to a particular point of time, but 予定 is not concrete enough as an
event. You have that plan now. What you have on Saturday is whatever you plan
to **do** , not the plan itself. The listener can, and will, still make sense
out of it by understanding 予定 as meaning すること as I said in the linked
question, but that doesn’t necessarily make the sentence completely natural.

That said, there are times when に is the best, or least bad, choice in a
subordinate clause. This happens because a time expression like 土曜日 being used
as a standalone adverb with no particle seems detached in a subordinate
clause, and は could add an unwanted sense of contrast.

> 土曜日 **に** 予定があるか彼に聞いてみよう。

When an added sense of contrast is not a problem, は is preferred.

> 土曜日 **は** 予定があるので行けません。

Whether an expression sounds natural or not is not a black-and-white matter.
It is a function of multiple factors.




I think the reason they sound a bit off as standalone sentences compared to,
say, 月曜日に試験があります is as follows. に as the time marker expects an event to be
bound to a particular point of time, but 予定 is not concrete enough as an
event. You have that plan now. What you have on Saturday is whatever you plan
to **do** , not the plan itself. The listener can, and will, still make sense
out of it by understanding 予定 as meaning すること as I said in the linked
question, but that doesn’t necessarily make the sentence completely natural.

That said, there are times when に is the best, or least bad, choice in a
subordinate clause. This happens because a time expression like 土曜日 being used
as a standalone adverb with no particle seems detached in a subordinate
clause, and は could add an unwanted sense of contrast.

> 土曜日 **に** 予定があるか彼に聞いてみよう。

When an added sense of contrast is not a problem, は is preferred.

> 土曜日 **は** 予定があるので行けません。

Whether an expression sounds natural or not is not a black-and-white matter.
It is a function of multiple factors.

