How long have you been on it, @LibbyA - Many Oncs will give you 2-4 weeks 'holiday' after 6 months+ if the side effects are really affecting you. Having one day off now & then wouldn't normally make a difference - but good that you had that day of respite anyway!
I've been on it (Arimidex) for some months now & am hardly having any side effects (so far!) I had shocking side effects with Letrozole (only lasted 6 weeks) and then tried Exemestane & was good for 6 months before the side effects showed up again! So happy to stay on Arimidex just now!!
My thumbs were a real problem but they've come good now. Fingers crossed, it stays that way!!
Take care, all the best