January 1(New Year's Day) : Make Love Not War

: Make Love Not War April 22 (Earth Day) : A skull with a recycling sign.

: A skull with a recycling sign. May 5 (Cinco De Mayo) : Toady Was Live!

: Toady Was Live! July 4 (Independence Day) : BBQ at Bob's Place (this is a reference to Marathon in which you kill BOBs or BOB-B-Qing).

: BBQ at Bob's Place (this is a reference to Marathon in which you kill BOBs or BOB-B-Qing). July 7 (Bungie Day) : Seventh Column Symbol.

: Seventh Column Symbol. October 31 (Halloween) : A gravestone that has the initials "R.I.P."

: A gravestone that has the initials "R.I.P." November 11 (Veteran's Day) : Kilroy Was Here.

: Kilroy Was Here. December 25 (Christmas): A Christmas light with an X on it.

It's almost Veterans Day, which means if you haven't unlocked the Elder Signs achievement yet in Halo: The Master Chief Collection you can do so on November 11, providing you've already collected one sigil.The Elder Signs achievement requires you to find two different sigils on the Halo 3 map Valhalla. These Sigils only appear on certain days of the year, making the achievement a pretty hard one to get. On November 11 he sigil "Kilroy Was Here" will be available to find. You can only obtain one of these sigils on a handful of notable days of the year. According to TA member Yazite 's Achievement Guide, the sigils can be found in the Forge, custom games and even in matchmaking. The dates and the sigils that can be found are included below:There is an offline method that involves changing the date on your console to one of the above, but many community members are reporting that this no longer works, so your mileage may vary.The achievement has only been unlocked by 6% of the 14,010 community members on-site, giving Elder Signs a TA Ratio of 4.05. Once you've knocked out this time-specific achievement, you can work your way through the excellent Halo: The Master Chief Collection achievement walkthrough written by LifeExpectancy.The next time you can grab another sigil will be on Christmas Day, shortly followed by New Year's Day. Make sure you subscribe to our Achievement Reminder news category where you will be sent a PM every time we make a post about achievements that become obtainable.