If the Christmas period wasn't already busy enough, those pesky game developers just have to take it a step further for achievement hunters by sticking achievements in their games that can only be obtained on certain days of the year. The achievements listed below can either be fully unlocked over the holidays, or progress can be made on the day towards unlocking said achievement. So, if you find yourself with some free time on one of the following days, consider jumping into these games.First up we have the You're a Mean One achievement in The Swindle . This can only be unlocked, December 24. You'll need to clear a house in The Slums with 100% loot collected on Christmas Eve (you heartless person). We have already had an unlock today, so it does look like it's working.Next, we have the Elder Signs achievement in Halo: The Master Chief Collection . You'll need to jump into Halo 3s Valhalla map in either Forge, a custom game or matchmaking and find a unique Christmas light sigil. To unlock the achievement, you'll need to find two of these sigils on specific days of the year. Unfortunately, you can only obtain one sigil per specific day. If you grab this one on the 25th, you'll be able to grab another sigil on January 1 — providing the New Years Day hangover isn't too bad! If you miss the New Years Day sigil, you'll be waiting until Earth Day on April 22. For more information on the Elder Signs achievement, check out the guide Sticking with Halo: The Master Chief Collection , we have the Destination Vacation achievement. You'll need to load up the Zanzibar map in Halo 2, again in either Forge, a custom game or multiplayer and look at a sign on the beach for a special Christmas message. For this achievement, you only need to view a single seasonal sign, so you'll unlock it immediately. If you miss it on December 25, you can grab it again on January 1. Check out the guide on where to find the seasonal sign.Moving on to the Storyteller achievement in Batman: Arkham City . You'll be able to grab this achievement(or at least make progress to completing the requirements) on December 25 in the Xbox 360, One and Win 10 versions of the game. Storyteller requires you to talk with Calendar Man on 12 specific days of the year. You'll find him in the basement of the Solomon Wayne Courthouse which you gain access to at the beginning of the game. Visit him, and he'll tell you a lovely little story, and you can cross off one of those 12 specific days. Make sure you visit him on January 1st for another story. Looking at the achievement guides, there are ways to do this by turning off your console and changing the date. Your mileage may vary on this, but you can find more info on how to do this, here The next achievement we have is Merry Quizmas in It's Quiz Time . All you need to do is play the game on December 25 to unlock the achievement — pretty straightforward. Just recently, the developers fixed an unobtainable achievement in the game a full two years after the game's release. However, members of the community are reporting that the Full House achievement is no longer unlocking, possibly due to the patch.You can also unlock the You Wasted Your Life achievement in Saw 2: Flesh & Blood . This is an Xbox 360 game that is not backwards compatible and has been removed from the Microsoft Store. All you need to do is load up the game and press the Start button once you reach the game's main menu.And finally, there is the Go Shorty achievement in Dance Central 3 . Again, this is a non-backwards compatible Xbox 360 title that has been removed from the Microsoft Store, and it requires you to have a Kinect. To get this one, you'll need to complete the song "In Da Club" with Oblio. You can also obtain this achievement on December 31 by completing the song with Dr Tan instead.Make sure you subscribe to the Achievement Reminders news category to receive PMs or e-mails each time we post a story about achievement reminders like this one. If you know of any other time/date-specific achievements that fall over the Holiday period, let us know in the comments. Have a good one!