Wednesday is the worst day of the week to advertise on Facebook, while Saturday and Sunday are the best, according to a new report analyzing user activity from brand pages of the world’s biggest companies.On Wednesday, the rate at which users “like,” share or comment on Facebook brand posts is 7.4 percent below the average daily interaction rate, according to the report by Buddy Media, a social media consulting company. The weekends, however, show a spike in engagement. Brand posts published on Saturdays and Sundays receive 14.5 percent more interaction compared to weekday posts.Yet many companies advertising on Facebook are doing it all wrong. Only 14 percent of posts published by brands appear on the weekend, while Wednesday is the most common day for brands to post Facebook...