Currently it's 09:30 AM here(while i write this).
At 3 AM tonight we had a power off. In a large area in center of a city. My router uptime was saved by my UPS =)
I was silently playing HL ( can't I? ) and listening to music, and then WHOOPS... i thought at least the link won't go down but seems like one of critical routers was in this area. Usually we have a power offs less than 1 time per month, with a length of a few seconds or minutes. And usually link stays up since our ISPs router...