Can i state the obvious reflect on if this question even makes sense?
We are currently the 2024 year since we began counting and probably didn't do so from day 1. Instead we took a significant cultural event and marked it the beginning. Adapting any initial time keeping to it.
We centered the beginning of this count on the life of someone who we cant proof ever existed. Great start.
we have likely been tracking sun cycles from much before but we cant exactly call our time keeping records reliable scientific measurements. Different civilizations and cultures had different ideas, may dispute data and eventually all had to make way for the teaching of the church.
There is no year 0, the calendar is a construct of time But doesn’t keep nor measure it.