27 May marked a momentous Monday for people who ascribe significance to the interval between 22 December and 19 January everywhere, as it was on this day that Capricorn left Capricorn.[1]

“What?”

For those suitably stocked up on the applicable jargon, it was on this date that the point on the ecliptic with right ascension 20h referenced to B1875, and demarcating the western edge of Capricornus, now has an ecliptic longitude greater than 300°. Armed with this knowledge, you can go do something else now.

“Huh?”

Okay, so we need to step back a bit. Then step back another …