Not a real suggestion, but I don't want to add it directly in the "Events" section because it may interfere with other events. I haven't talked this with anybody but this is how it'll be:
What time will it be? I don't know. How long will it last? Depends of my mood and the amount of people in.
If you wanna join log in at some point that day and wait. I won't give a time because I rarely follow them. You can't log in that very same day? Too bad, wait until the next party... If there's any. The day WON'T be changed, it'll happen that day at some point. And this is freeroam bullshit, for DMing you have any other day.
I'll be there. Will you?