temperatures. It's a temporary override - the program will continue as normal at the next state change.
want the temperature to be for the next (specified number of) hours. It resumes with the normal programme when that time expires. So if, for example, it's due to go to the overnight setting at midnight but you decide to go to bed at 10pm, you put it in party mode at a lower temperature for two hours, and leave it to do its own thing after that.
It would be even better, in my view, if it had a programme advance button - to make it move to the next programmed temperature immediately, and then carry on as normal.
[1] Although the normal use of Party Mode would be to maintain a higher temperature for longer - like when you're having a party - it's also useful for *lowering* the temperature for a specified period when you go out shopping or go to bed early.