Over the past twenty years financial economists have documented numerous stock return patterns related to calendar time. The list includes patterns related to the month of-the-year, day of-the-week, day-of-the-month, and market closures due to exchange holidays to name a few. Calendar anomalies are not in accordance with the concept of the Efficient Market Hypothesis. However, the simple observation of these anomalies are far from convincing, and do not contradict the EMH unless they can be used to provide exploitable profit opportunities.