Am I missing something of did Anderson make a big mess up in the time line when writing Afterlife?? According to the vorige 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 jaar and half sence getting the chopper in the desert. And when finding clair in alaska its six months after the attack on the japan facility.so from this u can see it took alice and her clones a jaar to reach japan. If u do the math w/ the first three films u know its been 5years allready at the end of extinction.add a jaar and u got SIX!!!!??