It seems fitting that, at the end of a year of learning and recording lessons, I would have to re-learn and re-post something learned only one week ago!
December 30 seems like a few-commuter day, right? And 3:30 is a nice early time to leave the city, even a really big city like New York, right?
Wrong!
January 30 is New Year’s Eve Eve, so even if a smaller number of people are leaving the city for the holiday weekend, they ALL leave at the same time! Which, apparently, is about 3:30!
I have learned, I really hope for the last time, to treat these days as high commute days and get out really really early, or very late!
Jane's Lessons Learned 
If this is a recurring theme, maybe you could go through your calendar and make a note on those days you think will be bad. Or other random things you want to be reminded of, like “make dentist appointment now”. I do this in Outlook. It sounds really dorky, but I’ve learned that keeping thoughts like this (important, but not needed very often) in my head is an exceptionally bad idea. I try to write things down where I’m most likely to see them again.
(writing this made me start wondering how the world might be different if everyone did this…what if Julius Caesar had tagged 3/15 “bad day to travel to the Senate”? did Windows XCVIII even support Outlook?)