noun
substitute national holiday; compensatory public holiday
A weekday designated as a public holiday when a national holiday falls on a Sunday, under Japanese law.
今年の敬老の日は日曜日なので、翌月曜日が振替休日になります。
Since Respect for the Aged Day falls on a Sunday this year, the following Monday will be a substitute national holiday.
noun
compensatory day off; lieu day
A day off granted by an employer in exchange for working on a holiday or other designated day; not a national holiday.
祝日に出勤したので、金曜日に振替休日を取るつもりです。
Since I worked on a public holiday, I plan to take a compensatory day off on Friday.