I think whatever I say, as long as you don’t look at your situation and take responsibility of everything in your experience, you won’t experience the freedom you seek.
Just realize the impossibility of answering this question logically. To give you an exhaustive logical rule to determine the amount of days that is acceptable to miss work per year.. is almost impossible. (At best I can give the following logical approach that is pointing beyond a logical approach):
Why? Because the answer is not in the mind. You need to live this moment and see what action is the most responsible to take for yourself. This is akin to the nonsensicalness of me sitting in front of my computer and telling you how much of that salad (or whatever you are eating) you should eat right now. You are missing life so your mind starts to ask questions like this. If you lived it totally right now, you would have the clarity to take whatever action you need for that moment. And no boss should have the authority over deciding this for you if you truly determine that you need to miss work when you sincerely look at your situation. That you must ensure from the beginning when you are signing a contract or giving a promise. Don’t ever give the right to anybody else to override your sense of truth. Looking at this answer you may tell that with my current understanding, I would never bow to any boss to make the decision of how much I should work. The moment I bow, that moment I have lost my authority. If we should bow to anything, that must be the truth of the situation. If the situation demands it, we should work and not miss work. Actually, bowing to truth is the work itself. Work should not be in any way in conflict with what you know to be truth. According to me, this is the ideal path, and the more we deviate from this the more we will suffer and have problems.
So, as an example scenario.. You are sick and your boss insists that you come to work that day. You know that it is not urgent and you would better rest not to compromise your health. You know that he is in his head and is remaining unaware of your situation due to not taking responsibility for your well being. Your heart knows that going to work like this will just empower an unhealthy pattern more. If you choose to go, the boss will feel more righteous, you will feel more miserable and experience less integrity, having ignored what you know to be truth.
Another scenario: You are very sick. But you know that if you be there that day, it can potentially save many lives or prevent a disaster. You feel within yourself that going is the better thing to do. You go. And you already feel better because you brought more Love to this world. The boss was about to call you, but you called him first, and he was moved by your integrity. You work that day and both you and the boss learn a lesson that day of being responsible to work on preventing that such a problem will ever happen in the future.
You have the innate power to be your own authority, but you need to awaken to this.