The Dutch word for day is
dag

Dutch Definition

day
1. dag, etmaal

dag	©
1. n-m. day (period of 24 hours)
We gaan over twee dagen op vakantie. - We are going on vacation in two days.
Een dag duurt 24 uur. - A day lasts 24 hours.
2. n-m. daytime (time between sunrise and sunset)
De dierentuin is geopend tijdens de dag, zodat bezoekers de dieren in hun natuurlijke omgeving kunnen zien. - The zoo is open during daytime, so visitors can see the animals in their natural ha
We genieten van de zon en het strand tijdens de dag. - We enjoy the sun and the beach during the daytime.
3. n-m. (in compound words) a meeting or assembly with legal or political power, originally convened on a specific day; a diet
4. interj. hello, short for goedendag 'goodday; goodbye'
5. interj. goodbye, same shortening
6. n-f. A piece of rope, used to punish sailors with, on the spot or in running the gauntlet
7. n-f. A line used to fasten young sailors while training boarding a hostile ship or climbing the rigging