1.
seven days
A period of seven days.
七日かかりました。
It took seven days.
七日間の休暇です。
It's a seven-day vacation.
あと七日で終わる。
It will be finished in seven days.
七日も待った。
I waited for seven days.
七日ぶりに会った。
We met for the first time in seven days.
2.
seventh day of the month
The seventh day of any month.
七月七日は七夕です。
July 7th is Tanabata (Star Festival).
七日に届きます。
It will arrive on the 7th.
来月七日に会おう。
Let's meet on the 7th of next month.
七日までに提出してください。
Please submit it by the 7th.
七日は予定がある。
I have plans on the 7th.
七日 uses the native Japanese (wago) counting system. It means both "seven days" (a duration) and "the seventh day of the month" (a date).
DAYS OF THE MONTH (1-10):
- 一日 (1st)
- 二日 (2nd)
- 三日 (3rd)
- 四日 (4th)
- 五日 (5th)
- 六日 (6th)
- 七日 (7th)
- 八日 (8th)
- 九日 (9th)
- 十日 (10th)
Note: From the 11th onward, Sino-Japanese numbers are used: 十一日, 十二日, etc. Only the 14th (十四日), 20th (二十日), and 24th (二十四日) retain special readings.
CULTURAL NOTE:
七月七日 is 七夕 (Star Festival), celebrating the annual meeting of the deities Orihime and Hikoboshi.