I watched an American tv program and one guy said to another: "You're off for that?". From the context I gathered that it meant "Have you changed your mind about doing that?", as doing that could be dangerous. Sorry - no more context.

Do Americans use that when they don't want/can't do something, like meet at some place with firends? Like in: "I've just learned that I go to London tomorrow so I'm off for Monday/the party,etc."

And analogically"

"Are we still on for Saturday?" (confirmation of an earlier arrangement)

Am I right about that?

Can you give me more diverse examples of these phrases?
And more importantly, what are some other ways of expressing the same?

I am American, but I've never heard the phrase 'off for' meaning 'no longer planning to do'. 'On for + event' is common and its meaning as you state.

There is also 'up for', meaning 'willing to do / interested in doing': Are you up for going skiing this weekend?
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Thank you!

If the programm airs again, I'll try to hear that one more carefully.

Anyway, thanks for the confirmation about 'on for'!
How else can you express the same in the similar colloqial way?

Like "Are we meeting on Monday?" Is it more lika a confirmation of mutual arrangement or a proposition? I would suspect the former. But how is it in fact?

And also, do you have some expressions with 'set' carrying similar concept?
Are we (still) meeting on Monday?-- Yes, a request for confirmation of an assumption.

Is the meeting (still) set for Monday? carries the same meaning.
How about "Are we still set for Monday?"

Thanks again!
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