I was probably too flippant with my original explanation June see if this makes sense . One aspect of the equinoxes is that the sun and moon get closer to each others setting and rising points .When there is a full moon just before and just after the equinoxesif circumstances are right it will appear red and have a 30% chance of eclipsing that night .Visually the moon would be sun like , full and red then possibly disappearing , far more striking than major or mainor standstill moons which are often not even seen , it could also be seen as the lunar marking of the mid way point of the solstices .WKLB points to the part of the horizon where that would have taken place within a decade of the build date , it is not a regular event .The same moon but necessarily red and eclipsing is used to calculate Easter .Unfortunately it is a bit convoluted .Hope that helps .Come to think of it Gordon just explained the last bit far more clearly