Haircuts: May 2027

Best days of the month

• excellent day: 12, 13, 14, 15
• good: 5, 16, 17, 23, 24
• tradition advises against: 1, 2, 10, 11, 28, 29

Two full moons, one sign

Across the two years behind this table, the gap between consecutive new moons averages 29.5 days and swings between 29.28 and 29.81 - a spread of about thirteen hours, caused by the Moon running faster near perigee. Because that average is shorter than most calendar months, each lunation creeps a little earlier in the month, and once a year the creep lines up so that two full moons land on the same date. When they do, the Sun has advanced almost exactly thirty degrees between them, so the point opposite it arrives at the far end of the same sign instead of moving on to the next. For the haircut list this changes nothing directly: neither Scorpio full moon touches the favoured days, which run from the 12th to the 15th, and May keeps the usual thirteen sign changes of a thirty-one-day month.

Days of May 2027

This is folklore, not dermatology: the Moon’s position on this page is computed with Swiss Ephemeris, no research links the phase to hair growth, and a haircut on an “unfavourable” day harms nothing. How the rules work.