I did not count vacations, including breaks from school (when I would typically go home) or vacations from home (when I would go elsewhere that is not home). I don't think that's what they mean by dates of physical presence. I understood it as when you returned to California. One criteria I used is whether or not I changed my mailing address. So, summer/holiday/vacation breaks would not typically count, whereas after I graduated I returned home (at least temporarily, for about a year before leaving again). My mailing address changed (back to my Cali address) for that year, hence I was "physically present" by their criterion. Also, I was not born in California, so this made things easier. I did not have to count the first 10 years of my life. I lived in the state until I left for college. So, this is really where the count started for me. I was in and out of California from college until now. (I am currently in Boston.)
Did you go to and graduate from a California high school? If so, they may ask you to sign an affidavit because there is a policy in which graduates from a California high school can petition for the in-state tuition.