I started to type "add the break for your birthday, silly!" ... but reviewing your original proposal I see the whole point was "I will not change the slope on these goals at all so help me God" (:
Still, that's the point of the akrasia horizon. Changing your mind outside the horizon should always be fine. Except that past-you apparently intended to take that option away from now-you. (: So, yeah, tricky.
But, ok, I guess that's the point of taking a poll. We get to be the arbiters of what past-you would've said had we asked it "what about a break for your birthday?" I'm going to say past-you would've been like "ok, fine, except for my birthday!".
Vote: Add the breaks.