It says that yesterday was your last day for posting, which means any scores you shoot in your New York region between now and next April should not be posted. If you travel somewhere where their season is still or is always open, you should post those scores as you shoot them.
I almost made a mistake by posting an after-season score once, and either the USGA's or my course's computer (I can't remember which) stopped me from posting it. I'm not sure that will occur for you, but it's possible.
Here's a chart on other New York region's and other place's closing dates:
http://www.usga.org/handicapping/education...ision-Schedule/