In this sentence, "when" vs "if"?

Question

There's a sentence written in my textbook, and I have some question about 'if' and 'when'.

1. The only times we would go to a restraunt was if it was a special occasion.

I think 'only' and 'if' goes well together to emphasize that we would never go to a restaurant if there was no any special event.

2. The time we would go to a restaurant was when it was a special occasion.

In this context, it is possible to go to a restaurant on days when it was not any special event.

So,

I'm curious if it would be legitimate use if I said like this.

3. The only time we would go to a restaurant was when it was a special occasion.

I think it is possible, but it would be the best to use 'if'.

Am I right to think this way?

Answer 1

No, you are not right to think this way. Number 3 is probably the best rendering—"when" actually correlates better with "time" than "if" does. (But #1 is also grammatically correct, if not so elegant/consistent.)

As for #2, it would probably be understood the same as #1, even though it does not say "only". The default assumption is that if you say "the time" (or rather "the times"), you mean "all of the time(s)"; so, that would not leave any other "times" that were NOT special occasions.

To leave open the possibility that you might go out to a restaurant on other non-special occasions [and that you might not go to a restaurant on ALL special occasions] say "on special occasions, we [usually] go out to a restaurant."