According to
Red Dwarf, deathday is the
anniversary of the day a
hologram died.
Living people
celebrate birthdays,
dead people celebrate deathdays. The very first deathday celebration in Red Dwarf is held in the first episode,
The End, for
George MacIntyre which they held right after his
funeral.
You also get to see
Rimmer's deathday celebration in Red Dwarf in the episode
Thanks for the Memory, when the crew hang out on a small
moon playing
air guitar and
getting drunk. It is the wee hours of the morning following his celebration when Rimmer explains to
Lister he's only had
sex once, with
Yvonne McGruder. Lister sympathizes with Rimmer, and decides to give him
Lisa Yates as a present.
See also
gazpacho soup.