[Sashimister]

Originally Posted by ByTheWay

I'm having difficulty with an example used in Japanese for Busy People II:

今時間がないので来週会ったとき話しましょう。

I'm not sure why た form is used before とき because the event is taking place in the future. So why wasn't the example written like this:

今時間がないので来週会うとき話しましょう。

My only guess is that it has something to do with both actions taking place simultaneously. I'm unsure about this, it feels a bit vague, so I'd appreciate any comments.

This た doesn't indicate the past tense. 会った is the attributive form modifying the noun 時.　If a teacher says "I will only accept typed papers.", that "typed" isn't in the past tense, either.　

今時間がないので来週会ったとき話しましょう。 means that the speaker and listener want to meet and talk next week.

今時間がないので来週会うとき話しましょう。 is not necessarily an incorrect sentence but if a native speaker ever said this, it would mean that the two persons are already scheduled to meet next week and they want to talk about something that has little or nothing to do with the original purpose of the meet-up.