When you have had enough, done enough, tolerated enough, held it together long enough and you need a day to say F@*k it ALL. Nothing gets done but the bare minimum on this day. Kids feed themselves. Kids feed the pets. Your significant other leaves you alone. Calls don't get answered. Laundry doesn't get done. You get the point. F it!
Sorry, it's my F-day. Ask me tomorrow.
I'm tired of this sh@! I need an F-day.