                 dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
             }
             
+// MARK: Beginning of hour
             it ("can calculate the beginning of an hour for date at the beginning of the hour") {
                 let beginningOf7AM = dateFormatter.dateFromString("2015-09-08 7:00:00")!
                 expect(TimeUnit().beginningOfHour(beginningOf7AM)).to(equal(beginningOf7AM))

                expect(TimeUnit.endOfMonth(randomDateInSeptember_2015)).to(equal(endOfSeptember8_2015))
            }
            
            it ("can calculate the end of a year for date at the end of the year") {
                let endOf2015 = dateFormatter.dateFromString("2015-12-31 23:59:59")!
                expect(TimeUnit().endOfYear(endOf2015)).to(equal(endOf2015))

                expect(TimeUnit.beginningOfHour(randomTimeIn7AM)).to(equal(beginningOf7AM))
            }
            
// MARK: Beginning of day
            it ("can calculate the beginning of a day for date at the beginning of the day") {
                let beginningOfSeptember8_2015 = dateFormatter.dateFromString("2015-09-08 00:00:00")!
                expect(TimeUnit().beginningOfDay(beginningOfSeptember8_2015)).to(equal(beginningOfSeptember8_2015))
