その年がうるう年かどうかを確認し、うるう年情報を取得します。
閏年とは、暦年を天文年と一致させるために、1日（2月29日）が追加される年です。閏年は4年に1度発生しますが、100で割り切れるが400で割り切れない年は例外です。
Check which years from 2025 to 2040 are leap years.
2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040
2025 is not a leap year. 2026 is not a leap year. 2027 is not a leap year. 2028 is a leap year. 2029 is not a leap year. 2030 is not a leap year. 2031 is not a leap year. 2032 is a leap year. 2033 is not a leap year. 2034 is not a leap year. 2035 is not a leap year. 2036 is a leap year. 2037 is not a leap year. 2038 is not a leap year. 2039 is not a leap year. 2040 is a leap year.