Folks give it up. It's a date on the lunar calendar. You can't argue it doesn't exist or you don't believe in it. It's like saying you don't believe in the 10th day of November.
It's a definition of a time the recurs periodically according to how it is defined. To say you disbelieve in it is to commit a semantic fallacy. "I call the perceive color of this scarf red." "Well, I don't believe in red."
So, what does ‘year’ mean?