Am I missing something または did Anderson make a big mess up in the time line when 書く Afterlife?? According to the 前 movies&my math at the begining of the movie when it says "four years later" it should be SIX!!???

Alice makes it clear upon meeting up w/ clair again its been a 年 and half sence getting the chopper in the desert. And when finding clair in alaska its six months after the attack on the 日本 facility.so from this あなた can see it took alice and her clones a 年 to reach japan. If あなた do the math w/ the first three films あなた know its been 5years allready at the end of extinction.add a 年 and あなた got SIX!!!!??