Is it possible, do you think, to be allergic to a particular day of the week?

I'm serious...I take Claritin every single day, and it does the trick. Except on Sunday evenings, it seems that I happen to break into a hay fever attack in the evening oddly enough every now and then.

I've ruled out a few things:
1. It's not the house or the room I'm in, because I used to have these hay fever attacks at PFW on Sunday evenings when I was at work, and even had them before that, though I can't say for sure that they were on Sundays, specifically...though I think I remember a couple Sundays where I was leveled by hay fever attacks.
2. It's not the dog, nor am I regularly around a different dog or cat on those days, because this was happening before I went by my parents' house on Sundays, and if it was Kazak, I'd break out in a hay fever attack on Saturdays too.
3. Although I do eat slightly differently on Sundays, it's not anything unusual. Just a bigger meal during the day and a smaller evening meal, if that.

The things I haven't ruled out are that it only happens on Sundays in the fall--but I've always known that the fall is a much more difficult time for my allergies anyway...I just want to narrow down why it happens on Sundays in the fall. Because, the weirdest thing is this: I didn't have a hay fever attack on Sundays regularly until I started this freelance editing work. Like, when I was hanging out at my parents' or Gina's parents' house(s) on Sundays, I didn't have this problem.

So, maybe I'm allergic to editing on Sunday nights. Does anyone think that's possible? And I'm only half-joking here. Maybe there's some dots that I'm not connecting...any wild ideas?