"You are one year older at the end of the day (12:00am) before your birthday."
- "You are one year older at the end of the day (12:00am) before your birthday."
"you are one year older" 「一つ年を取る」"you turn one year older" も言えます。
"at the end of ~ 「〜が終了時に」
"the day before ~" 「〜の前日」
"your birthday" 「誕生日」
You turn one year older when the day before your birthday ends.
"誕生日の前日が終了する時（午後12時）に一つ年を取る"
- You turn one year older when the day before your birthday ends (at midnight).
- You become one year older when the day before your birthday ends.
4月1日生まれのひとは，前日の3月31日の深夜12時を迎えた瞬間に年齢が1つ加算される。
- Those who are born on April 1st become a year older when midnight of March 31st comes to pass.
オーストラリア 
アメリカ合衆国 
