  Humans like to party, and New Year celebrations are a great way to do that.
However New Years celebrations that rely on an orbital year don't line up with
those that use a Lunar Calendar, as there are currently 12.368 synodic months
(moonths) in a year. There is cyclostratigraphic, paleontological, and tidal
rhythmite data that reveal that over billions of years the interplay of angular
momentum between the Sun, Earth and Moon has changed the rate of rotation of
Earth, and at the same time evolved the orbit of the Moon, and therefore the
length of a Lunar month. Using a subset of this data and referencing literature
models of the Moon's orbital evolution, we create our own simple model to
determine "True Happy New Years", time periods when there were an integer
number of lunar synodic months in an Earth orbital year. This would allow
modern calendars to pick a shared New Year's Day, and party accordingly. We
then predict the next True Happy New Year to be in 252 million years, and offer
suggestions to begin the party planning process early, so that we as a planet
may be ready.
