Meaning of CALENDAR YEAR in English

CALENDAR YEAR

noun Date: circa 1909 a period of a year beginning and ending with the dates that are conventionally accepted as marking the beginning and end of a numbered year, a period of time equal in length to that of the year in the calendar conventionally in use

Merriam Webster. Explanatory English dictionary Merriam Webster.      Толковый словарь английского языка Мерриам-Уэбстер.