noun
Advent calendar
A calendar used to count down the days of Advent, often with small doors or pockets containing chocolates or gifts. Used in Japan especially around Christmas.
子供たちは毎朝アドベントカレンダーを開けるのを楽しみにしている。
The children look forward to opening the Advent calendar every morning.
Variant with interpunct; less common but still seen.
From English 'Advent calendar'.