Where is the function to ask friends for certain activities?

As far as I know, this function does not exist in Facebook. However, I would think it would be one of the most straightforward and obvious ways of using Facebook. Does this really not exist?

It could be called Activity request. Right at your front page you can choose whether your activity readiness is off, on or neutral. You could also make automatic schedules such as you're off on weekdays at certain hours.

You can then ask all your friends, who have readiness on or neutral, to join for whatever activity you have on your mind. You can set such freely written requests as (you could also specify if it's targeted for couples or males/females, a selected group of your friends etc.):
- Badminton this weekend?
- Dinner at our place this Friday?

Then, once the request is sent, all friends who match (e.g. selected group of friends of certain age) will get notifications of the request. If your readiness was on, you'll get an email. If it was neutral, you'll only get notification while you're online. Then, once the match is accepted, the request will automatically close. (And the two friends can go and play badminton on Saturday, for example.)

If it's not obvious, there are many reasons why this is better than just generally asking the same question in your status. The most important is that it's much less uncomfortable making the question if there is already some information about the friends' availability beforehand and it's therefore more voluntary, less intrusive.