a period of time occupying a regular part of a calendar year that is used for some particular activity; "a school year"
ある特殊の活動に使用される通常の暦年の一部を占める期間
year
the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun; "a Martian year takes 687 of our days"