Can my employer make me wait over a year for my vacation time to renew?

(California)Every 12 months our Vacation time renews. My renew time is coming up in September (month I was hired) My employer wants to change the Vacation time to start in January for everyone, but for my situation this means I have to wait an extra 3 months for my vacation to renew. That means I would have to wait an extra 3 months WITH NO VACATION, because it is more convenient for him to have it this way. Is he legally allowed to do that? I feel robbed of my vacation as I am being forced to wait an extra 3 months (over a year) for my vacation to renew. I have been working here for 6 yrs, there was no discussion about it, he didn't warn anyone, no one was in agreement, he just did it.