Computus week before the Gregorian Easter in 1724, 1744, 1778, 1798, etc. The Easter cycle groups days into lunar months, which are either 29 or 30 days long. There is an exception. The month ending in March normally has thirty days, but if 29 February of a leap year falls within it, it contains 31. As these groups are based on the lunar cycle, over the long term the average month in the lunar calendar is a very good approximation of the synodic month, which is days long. There are 12 synodic months in a lunar year, totaling either 354 or
Dundrod Circuit the 2017 Ulster Grand Prix. The race record for the Dundrod Circuit is an average speed of set by Bruce Anstey during the 2017 Ulster Grand Prix. The lap record for the RAC Tourist Trophy on the Dundrod Circuit is 4 minutes and 42 seconds at an average speed of 94.67 mph (152.3582 km/h) held by Mike Hawthorn driving a Jaguar D-Type set during the 1955 RAC Tourist Trophy. The race record for the RAC Tourist Trophy on the Dundrod Circuit is 7 hours, 3 minutes and 12 seconds an average speed of 88.32 mph (142.139 km) for 84 laps