It depends on what company you are. Some who administers some SAP thing for a huge supermarket chain tells me they do all of their upgrades on weekends because

It depends on what company you are. Some who administers some SAP thing for a huge supermarket chain tells me they do all of their upgrades on weekends because their users aren't at work. Makes sense for them, but it would be a crazy thing to do the consumer-focused interweb company that I work for.