HEAVENS: A blue moon on Friday, July 31

Don't forget that this Friday, July 31, we will have a Blue Moon, the second full moon of the month. They occur every 2.5 years on average (accounting for the phrase "once in a blue moon"), according to "The Old Farmer's Almanac." And you've probably noticed how the days are getting shorter: on July 1 the sun rose at 5:10 a.m. and set at 8:24 p.m. The corresponding figures for July 31 are 5:35 a.m. and 8:05 p.m.