I'm having to come into the lab on weekends to get the fast-growing organisms I work with at the right stage of development for my experiments, I cannot predict the dates or times for that precisely (unless ~20 hours prior) because the time they take to get there depends on the mutations I never worked with before and their response to tiny fluctuations in temperature. Today (Saturday) I came in for ~6 hours and will have to come in tomorrow for a few hours. I found a day next week when I don't have to come in. My PI hates not seeing me in the office 9-5 every single weekday with no exceptions even at lunch time and even if I had to work late the day before or work weekends for the reasons described above. Is it still reasonable to tell my PI that I'm taking a day off because I had to work during the weekend? I ask because I expect them to get livid as usual. Can I complain to someone if they react like this over me trying to take control of my own work schedule?
I heard a suggestion earlier to change advisors - I can't find anyone else who works in this field at my institution and my research council funding can't be transferred elsewhere. I'm two months away from finishing my second year (out of 4 years of funding) so I'd hate to start my project again somewhere else.
Edit to make question more to the point and add: I'm not complaining about working weekends, I love working weekends. I did pull all-nighters before and I did work in the lab three weeks in a row before including weekends. I was happy with all of that but not happy with angry emails from my PI asking why I'm not at my desk at a certain time and why I left the office without their permission. It doesn't seem to matter how many days in a row I work or whenever I had to work at night, I feel I'm still not "allowed" to take time off. I don't know how to tell my PI that I shouldn't need their permission for this, but I feel they won't take it well.