The paper investigates an anomaly in the capital market commonly referred to as the Weekday Effect. The Weekday Effect means that the average daily stock returns differ between the different days of the week. Previous studies have examined the Weekday Effect in the US capital market in conjunction with the day of quarterly reports' release. Fridays have been documented where the release of quarterly reports has resulted in negative abnormal returns; this is referred to as the Friday Effect. Furthermore, previous literature has documented that quarterly reports released on Fridays contain "bad" news compared to releases on the remaining weekdays. This paper aims to investigate the relationship between the publication of quarterly reports on Fridays and a possible abnormal return in the Swedish capital market. Furthermore, the paper investigates whether quarterly reports published on Fridays tend to present earnings below market expectations. As documented, the study does not find a Friday Effect in conjunction with the publication of quarterly reports in the Swedish capital market, however, it is documented that the publication of quarterly reports on Tuesdays is negatively associated with a deviation return. Furthermore, the study does not document that the publication of quarterly reports on Fridays tends to contain "bad" news, however, it does document that the publication of quarterly reports on Thursdays tends to contain "bad" news. The study's results are not in line with previous documentation on the US capital market, however, it does document a difference in the day-of-the-week effect between the US and Swedish capital markets.