This is the 248th most frequent Dutch word.
maandag
Monday.
Here, 'maandag' is used to define and describe Monday's position in the sequence of the weekly calendar.
Maandag is de eerste dag van de week.
Monday is the first day of the week.
In this sentence, 'maandag' specifies the regular occurrence of an activity associated with the day Monday.
Op maandag ga ik altijd naar de sportschool.
On Monday, I always go to the gym.
In this sentence, 'maandag' is used to refer to the specific day of the week (Monday), indicating the day when the speaker starts their workweek.