Thomas Wolsey in particular) by two converted Greenwich friars, William Roy and Jerome Barlow, published in 1528 under the title Rede me and be not wrothe, for I say no thynge but trothe. The relevant passage reads: It is not clear from the context that this refers to intercalation; the context of the passage is a dialogue between two priest's servants, spoken by the character "Jeffrey" (a brefe dialoge betwene two preste's servauntis, named Watkyn and Ieffraye). The intention may simply be that Jeffrey makes an absurd statement, "the moon is blue", to make the point that priests require laymen to believe in statements even if they are patently false. "Betrayer moon" speculation In 2007, Joe Rao, Skywatching Columnist at Space.com, stated that many years previously he had speculated in Natural History magazine that the "Blue Moon Rule" might derive from belewe, which he described as an Old English word meaning 'to betray', because the extra full moon "betrays the usual perception of one full moon per month." He then added that his speculation had been "innovative", but "completely wrong". In 2009, a less detailed version of this speculation was mentioned in Farmers' Almanac. Maine Farmers' Almanac blue moons In the 19th and early 20th centuries, the Maine Farmers' Almanac listed blue moon dates for farmers. These correspond to the third full moon in a quarter of the year when there were four full moons (normally a quarter year has three full moons). Full moon names were given to each lunation in a season. The seasons used were those of the mean tropical year, equal in length, as opposed to the astronomical seasons which vary in length because the earth's speed in its orbit round the sun is not uniform. To compare, in 1983 the equal seasons began at 1.48 AM on 23 March, 9.15 AM on 22 June, 4.42 PM on 21 September and 12.10 AM on 22 December, while the astronomical seasons began at 4.39 AM on 21 March, 11.09 PM on 21 June, 2.42 PM on 23 September and 10.30 AM on 22 December (all times GMT). When a season has four full moons the third is called the "blue moon" so that the last can continue to be called with the proper name for that season. Sky and Telescope calendar misinterpretation The March 1946 Sky and Telescope article "Once in a Blue Moon" by James Hugh