I love you so much, Lee.
Moonphases are simple enough. If the moon is full then one gains a point of luck. If the moon isn't full then bad things are more likely to happen like the hissing of 'trices causing the player character to begin petrification. On Friday the 13th a point of luck is subtracted from the player character. Time is also a factor in-game because gremlins have special abilities at midnight, dogs howl at midnight and during a full moon along with undead being twice as dangerous to the player. In short the DevTeam thinks of everything. rec.games.roguelike.nethack simply plays catch-up to prove themselves more clever than the DevTeam.
Moonphases linger for a few days after the proper fullness and newness of our largest known natural satellite. So when 3/13/09 rolled around it created an unusual situation which is shown in the following screenshots. The meat of the matter is in the text at the top of the image.


Beware, gentle reader, if you are inclined for Friday the 13th comes once again in November.
February, March and November.
The next time this will happen is 6/13/14 and 9/13/19. November 13, 2014 and July 13, 2018 will have a new moon on Friday the 13th.
Speaking of dates I'm eagerly awaiting Saturday March 14th, 2015 at 9:26:53 a.m.
Why the fuck not. I should look at the letter and see if it's in cycling distance. Long hair? Beard? Riding a bicycle? HOLY SHIT I BET HE DIDN'T VOTE FOR GRAMPA AND DINGBAT!!!
Indeed but I'm for small government and individual liberties. I'm a Republican because Libertarians haven't accomplished dick or shit. I don't believe they've even gotten a fucking electoral vote.
I do plan on voting one last time in Colorado Springs before returning to spend the rest of my life with Lee.
Who knows where the rest of our lives will lead.