year

https://doi.org/10.1351/goldbook.Y06723
Non-SI unit of time, a = 31556952 s. The year is not commensurable with the day and not a constant. The value given corresponds to the Gregorian calendar year (a = 365.2425 d).
Source:
Green Book, 2nd ed., p. 111 (https://dev.goldbook.iupac.org/files/pdf/green_book_2ed.pdf)