げつようび月曜日getsuyoubi
1.

The second day of the week, following Sunday, typically recognized as the first day of the work or school week in many cultures.

2.

A day commonly associated with the beginning of new tasks or responsibilities, often viewed as a fresh start following the weekend.

3.

A calendar day designated for various events and activities, often linked to conventional business hours and routines.

Example:

月曜日はいつも憂鬱だ。