Confusion on date of Big Bang patch.

So. does the patch START on Monday night or Tuesday Night?

Wondering this too, although uncharacteristic, I'd guess the patch starts Monday night. We'll know tomorrow most likely

They will let you know when they post the notice.

Judging by how early they had 'Coming in 3 days' up tomorrow i'd say Monday night. It could be a screw up, ofc.

Monday night.

My guess is Monday night into tuesday, because of their "end of the world" event on Monday. I find it kind of strange they would have GM events on the second to last day of maplestory as we know it.

Going by the "end of the world" event happening Monday, and by the fact that the 17-day ring event has to end on the 23rd (so people have to be able to log in on the 7th after the patch), it looks like Monday night.
On the other hand they usually patch Tuesday nights.
We will not know until they post the official notice.

Yah, most likely. Otherwise many people would miss on the first day of ring event.