Hectaëteris

A hectaëteris is the Greek name for the period over 100 tropical years (also known as a tropical century or hectade or centade) where the Moon phase occurs over 5 days later.

It corresponds to 1,237 synodic months, 1,337.0100713736433 sidereal months, 1,342.387255070837 draconic months, 1,325.7098123607332 anomalistic months, and 36,529.337310185234 days.

Ben: The first full moon of 2022 was January 17.
Gregory: What's so special about that?
Ben: Betty White would've turned 100.
Gregory: She was special.
Ben: This means a full moon occurred around 5 days before she was born.
Gregory: I see.
Ben: Because January's full moon in 2022 was a hectaëteris after January's full moon in 1922, which was 37 years before the year Kirstie Alley was born.
Gregory: You mean 1959.
Ben: Yeah, on January 12.
Gregory: I see.
Ben: May she rest in peace as well.
Gregory: Sad.

by gregben October 2, 2023

Hexaëteris

A hexaëteris is the Greek name for the period within 6 tropical years where the Moon phase occurs around 6 days earlier.

It corresponds to 74 synodic months, 79.9828175276068 sidereal months, 80.30449221927401 draconic months, 79.30681173378679 anomalistic months, and 2,185.2635092592623 days.

Ben: The ultra supermoon 2016 was marked by the last lunar eclipse of 2022 after a hexaëteris.
Gregory: You know your stuff man.
Ben: Not to mention the last lunar eclipse of 2021 was a hexaëteris after my oldest grandfather's 81st birthday in 2015.
Gregory: Wow.

by gregben October 2, 2023