September’s full Moon is coming up, the so-called “Harvest Moon,” which is the full Moon nearest to the autumnal equinox (September 23rd). The arrival of this year’s Harvest Moon will depend on which time zone you happen to live in. If you live in the Eastern Time Zone, the moment the Moon turns full will occur just after midnight—at 12:33 a.m. on Saturday, the 14th. But if you live elsewhere in the country—in the Central, Mountain, or Pacific time zones—the moment that the Moon turns full comes before midnight on Friday, the 13th!
Split Time Zone Full Moon: How Often Does This Happen?
Interestingly, the last time this happened—June 13, 2014—it was the reverse of what will happen this month. It was a Friday the 13th full Moon solely for the Eastern Time Zone, with the Moon turning full just after midnight; for the rest of the country, the full Moon was the day before, on Thursday, the 12th. Nationwide we haven’t had a Friday the 13th full Moon since October 13th, 2000, and it won’t happen again until August 13th, 2049!
It has been calculated that to have a full Moon occur on the 13th day of a particular month, and for that day to be a Friday, it is (on average) a once in 20-year occurrence!