November 11th is Veterans Day in North America, which honours all of the people who once served in the United States Armed Forces. This day is also a special day in Halo: The Master Chief Collection
as it is for this reason that there's a chance for players to progress towards a date specific achievement.
The Elder Signs achievement is awarded for viewing two different sigils on Halo 3
's Valhalla map. By entering the map in Forge mode, in a custom game or in multiplayer matchmaking, you can view the Kilroy Was Here sigil. If this is only your first sigil, December 25th will be the next opportunity you'll get for this one if you don't want to go offline.
On a completely different note to the above, November 11th is the first of three opportunities this month to unlock the Go Shorty achievement in Dance Central 3
. Players will need to play the In Da Club track by 50 Cent while dancing as Mo to get this achievement.
The Go Shorty achievement in Dance Central 3 worth 44 pointsPerform "In Da Club" with a character on that character's birthday.
If November 11th is no good for you, performing the track as Bodie on November 23rd or as Glitch on November 26th will also unlock the achievement.