After reading many positive reviews on Steam and being a fan of the SimCity series, I decided to give Cities: Skylines a try on the Xbox One; however, I didn't have much time for gaming after buying the game. I skimmed through the achievement list and found this achievement. Seeing as it is possible to 'afk' this achievement, I decided to go for this achievement first. I was lucky enough to actually be present and see when the achievement popped. Because I didn't do anything else in the game before or while going for this achievement, I am able to share the exact amount of time it will take to pop this achievement as well as provide a basic guide including some hopefully valuable tips for anyone who wants to go for this achievement.
This achievement is very time consuming. If you are planning to actually play the game and unlock the rest of the achievements, you should leave this for last. (Don't do what I did.) You will probably put several hundred hours into this game by the time you unlock the rest of the achievements.
This achievement is for experiencing 1001 nights in the game. This should not be confused with the in-game date at the bottom left of the HUD. A night is experienced when the screen darkens. According to my final figures, on triple speed, a day/night cycle takes a little over 9 MINUTES.
In comparison, on regular speed, it would take almost 30 minutes.
The fastest way to unlock this achievement is to start a new map. You can select any map. Do not build anything on the map. This will prevent you from possibly going bankrupt and allows for less processing to occur which slows down time. Speed up time to 3x. On the Xbox One, you change the speed that time passes by clicking on the left thumbstick. You can check what speed you are currently at by looking at the bottom left of the screen. This area also shows the date you are currently at which is a good way to keep track of how close you are to unlocking this achievement. Make sure the day/night cycle is on in the options menu.Here are the accurate stats:
To experience 1001 nights in Cities: Skylines at 3X speed on a blank map, it will take:
6d 8h 50m of in-game playtime, that's
approx. 153 hours (152h 50m)
111156 Total Days Passed (in-game)
2324 Year Unlocked (starting year was 2018, I believe)
To get a more general picture of what this entails, I was leaving on my Xbox One for at least 12 hours a day. For several days, I left it on for almost 24 hours. Doing this it took approximately 2 full weeks to unlock, possibly a bit more.
Also, while going for this achievement by using this method one other achievement should unlock:
As far as I am aware of, this is the only way to unlock this achievement. If anyone unlocked this achievement in less time than this, it's either because they found some kind of glitch or they cheated. Like I mentioned earlier, from the first few minutes I put the game on, I was grinding this on 3X speed, and I literally saw the achievement pop, so my statistics are very accurate.
Just to clarify, this is a cumulative achievement. Nights experienced on multiple maps/saves count. That's why earlier in the solution I mention to leave this achievement for last if you intend on completing the game. Thanks to KingyOwl and Henri Stadzisz for confirming this.
If you have any questions or can provide any additional information, please leave a comment. Also, please leave a comment before voting negatively so that I can make any improvements or corrections.