lunation

A month of an average of approximately 29.53 days, measured from a lunar phase until the return of that same phase.

And there is not the moon seen in all the lunation, save only the second quarter.

The seventh annual Lunar Calendar challenges the traditional structure of the calendar from a feminist perspective. The Lunar Calendar bases its months bases its months on lunations or 28 day lunar cycles, giving us thirteen in a calendar year.

The irregular period from one new moon until the next.