Here - from Wikipedia:
Days begin and end at midnight, and months begin on the day of the new moon. Years start on the second (or third) new moon after the winter solstice. Solar terms govern the beginning and end of each month. A sexagenary cycle consists of stems (干, gān) and branches (支, zhī) is used as identification alongside each year and month; including intercalary months or leap months. The length of a month is also annotated as either long (大, literally “big” for months with 30 days) or short (小, literally “small” for months with 29 days).
Posting Wikipedia as authoritative?
And no, it’s not a stupid vanity to take note of a phrase like “Chinese New Year” suddenly leaving parlance in media and online.