The short answer to this question is 9 months. But you seem like the kind of person who must understand why this is true. There are several factors that play a role in the safety of foodstuffs but the big consideration is bacteria. How long would it theoretically take for bacteria to reach unacceptable levels in your chicken?
It is generally accepted that chicken and turkey are only good in the refrigerator for 1-2 days. This range offering comes from the USDA so it has some validity. If you have ever experienced meat, poultry or produce that has gone bad what you smelled or possibly tasted was the metabolic aftermath of bacteria.
So if we know that chicken will definitely go bad if we leave it in the fridge for too long then we know it has bacteria on it when we buy it. This is not a cause for alarm. You probably know that everything in you kitchen has some bacteria on it including you. A simplified way to look at the process of refrigeration and freezing is to think of it as slowing the process down. The colder it is the less work the bacteria can do. However this is not a truism.
Some bacteria can operate quite well at temperatures as low as -10. This type of cold operating bacteria is particularly present in some types of fish and that is why fish that has been stored in your residential refrigerator can sometime seem like it went bad sitting in the freezer. Turn your freezer down below -10 and store fish for the same amount of time and you will likely maintain healthy tasty fish.
In all of this information there are two small caveats to throw into the mix. The first surprise is that complex molecules will break down over time by themselves. This process is hardly appreciable compared to that of bacterial breakdown. However if you were to leave a piece of completely sterile chicken in a sealed container on the counter it would eventually turn to mush but it would be edible. This is why scientist store samples in -86 freezers. It slows the decomposition process for their sterile samples. The second surprise is there are what we call extremophiles that live and operate in temperature ranges and environments which would be inhospitable to most bacteria. However, chicken is not often exposed to such organisms and it would be a near miracle to find them in your home freezer.
In conclusion don’t leave you chicken in the refrigerator more than 2 days and dont leave it in the freezer for more than 9 months. Anything can happen but these recommendations will keep you safe from the everyday chicken. To all of you germaphobes out there forget i ever said extremophile as far as you are concerned they are not real.