The Dutch Timezone.

In the Netherlands, time is indicated by Central European Time (CET) during winter, which is considered standard time. This is one hour ahead of coordinated universal time (UTC 01:00). During summer as daylight saving time, the country observes Central European Summer Time (CEST), which is two hours ahead of coordinated universal time (UTC 02:00). The Caribbean Netherlands, comprising Bonaire, Sint Eustatius, and Saba, follow Atlantic Standard Time (AST) throughout the year, which is four hours behind coordinated universal time (UTC−04:00).

Before the 19th century, standard time zones were not in place across the country, and the time was measured using sundials, which were subject to inaccuracies. Other methods, such as the water clock, were used if the sky was cloudy or at night. Sundials, which were divided into 24 hours, were incorrect due to the Earth's rotation around the Sun, which does not follow a uniform time of 24 hours. Clocks were introduced in the 13th century, but remained imprecise and had to be adjusted daily based on the position of the sun with a sundial to remain accurate. Christiaan Huygens invented the pendulum clock in 1656, which used a pendulum as its timekeeping element. This clock was highly accurate, misaligning only about one second per year and was the standard timekeeper until it was replaced by the quartz clock in the 1930s.