Black Friday Sale more than 50.000 users simultaneously accessed the site, temporarily causing delays and server overloads. The overwhelming numbers of visitors also caused the servers of several online shops, such as the electronics store Saturn, to suffer significant downtime. Despite the technical problems, the first Black Friday Sale generated a significant turnover and was considered a notable success by online retailers and organizers alike. After successfully launching in 2013, and having a successful 2014, 2015 and 2016, the Black Friday Sale is set to return on 24 November 2017. Online shoppers are expected to spend billions on this Black Friday sale. Once
Common year starting on Friday has only one Friday the 13th; The only Friday the 13th in this common year occurs in August. Leap years starting on Thursday share this characteristic, but also have another one in February. This is the only year type where the "n"th "Doomsday" (this year Sunday) is not in ISO week "n"; it is in ISO week "n"-1. In the (currently used) Gregorian calendar, the fourteen types of year (seven common, seven leap) repeat in a 400-year cycle (20871 weeks). Forty-three common years per cycle or exactly 10.75% start on a Friday. The 28-year sub-cycle does only span across century