にちようび日曜日nichiyoubi
1.
The first day of the week, following Saturday, recognized as a day of rest for government offices, schools, and many businesses.
2.
A day traditionally set aside for relaxation and leisure activities, often associated with religious observance in various cultures.
3.
The day when many people take a break from their regular workweek, frequently spent with family or engaging in personal interests.
Example:
その店は日曜日は閉まっている。