noun
Sunday night blues; Sunday night syndrome
Jocular term for the mild depression or anxiety felt on Sunday evenings as the weekend ends and the work/school week approaches. Originates from the anime Sazae-san, which airs at 18:30 on Sundays in Japan.
日曜の夕方になると、サザエさん症候群で気分が沈む。
On Sunday evenings, I get the Sunday night blues and feel down.
サザエさん症候群を防ぐために、月曜の朝に楽しみな予定を入れる人もいる。
Some people schedule something fun for Monday morning to prevent the Sunday night blues.