weeknight
A night from Monday to Thursday during the school or work week.
A weeknight is any night from Sunday through Thursday, the part of the week when most people follow their regular school and work schedules. These nights feel different from weekend nights because there's another full day of responsibilities coming up the next morning.
On weeknights, families typically stick to routines: homework gets finished, bedtimes come earlier, and activities wrap up at reasonable hours. A parent might say “not on a weeknight” when you ask to stay up late watching a movie, saving that kind of fun for Friday or Saturday when there's no early alarm the next day.
The word helps distinguish between the disciplined rhythm of the regular week and the freedom of the weekend. Restaurants know weeknights are quieter than weekends. Sports leagues often schedule games on weeknights because weekends are reserved for tournaments. Notice that Friday night usually doesn't count as a weeknight, even though Friday is technically a weekday. That's because Friday night feels like the weekend has already begun, with Saturday's freedom just hours away.