this is perfective infinitive VS imperfect infinitive
Oh, and I thought the "c" makes it a future tense from some reason. Thanks for clarifying.

не могу дождаться, когда + future tense
Do you have to use когда ?


Can't it's just be:

Алекс: ты летишь за границу послезавтра?
Ира: Да, я не могу дождаться!


in Russian here you can say "Я с нетерпением жду встречи с ним",
lit. I don't have enough patience to wait to meet him, I am looking forward to meeting him....

Does it work in this scenario as well?:


Алекс: ты летишь за границу послезавтра?
Ира: Да, я с нетерпением жду!"