a contraction of 'year is' in informal speech (e.g., 'Next year's going to be better' = 'Next year is going to be better').

「'year is'の短縮形（口語で用いられる）」

the possessive form of 'year', used before a noun to indicate belonging, measurement, or association with a year (e.g., 'a year's supply').

「yearの所有・所属を表す（名詞の前に置かれる）」

a contraction of 'year has' used in perfect constructions (e.g., 'this year's been busy' = 'this year has been busy').

「'year has'の短縮形（現在完了で用いられる）」