👉 In astronomy, a novilunar period is a lunar calendar period that corresponds to the 12th month of the lunar year. It starts on the 19th day of the second month and ends on the 15th day of the third month. This means that it falls between the midsummer solstice and the winter solstice, which are the longest nights of the year in the northern hemisphere. The term "novilunar" is derived from the Latin word "nov