For when you want to know when the new or full moon days are, just look up the Chinese calendar.....
The Chinese Calendar
China and many Chinese communities around the world use the Chinese calendar, which predates the Gregorian calendar.
The Chinese calendar is a lunisolar calendar that is used to determine important festival dates, such as Chinese New Year.
Lunisolar calendar
The Chinese calendar is lunisolar. It is based on exact astronomical observations of the sun's longitude and the moon's phases. It attempts to have its years coincide with the tropical year and shares some similarities with the Jewish calendar. In both calendars, an ordinary year has 12 months and a leap year has 13 months; and an ordinary year has 353-355 days while a leap year has 383-385 days.
In Modern Society
Although the Chinese calendar originated in China, the Gregorian calendar is used in China for civil purposes in modern times. However, the Chinese calendar is still observed among various Chinese communities around the world. It is used to determine festival dates, such as Chinese New Year, as well as auspicious dates, such as wedding dates. It is also used to determine moon phases because it follows the moon.