MrPL, there's never going to be a time to quit that's "convenient" for the addict in your head. If you keep drinking through your event on Saturday, your addict brain will come up with something else to keep you drinking on Sunday.
There will always be temptations and challenges to your sobriety, and it is going to be hard--sometimes very hard. As someone said above, this is the fight of your life, and it is a fight FOR your life. You have to live with that fact, and arm yourself against it, rather than just keep putting off your sobriety until some time that seems more convenient.
Good luck. We are all here to support you.