The sun and the clock in Mar del Plata (2026)
Mar del Plata lies at 57.6°W. Its time zone, UTC−3, is built around the 45°W meridian. The 12.6° gap between them means the clock runs roughly 50 minutes ahead of the sun: solar noon arrives at about 12:50 rather than 12:00. The zone holds UTC−3 all year — there is no daylight saving here.
The longest day of 2026 is 22 December, with 14h 48m of daylight. The shortest is 22 June, with 9h 31m. The swing between them is 5h 17m. This is the latitude band where the difference between summer and winter evenings is most obvious.
The earliest sunrise and the latest sunset do not land on the longest day. In Mar del Plata the sun comes up earliest on 8 December at 05:21, while the latest sunset waits until 5 January at 20:16. The equation of time is what separates them: the Earth's elliptical orbit and axial tilt move solar noon back and forth by several minutes over the year.
The sky stays usably light for a while after the sun goes down. In Mar del Plata that civil twilight runs about 26 minutes at the equinox, stretching to 31 minutes at the solstice.
Every figure in this section is computed from the city's own latitude, longitude and IANA time zone using NOAA solar algorithms (Spencer, 1971), accurate to about ±2 arcminutes below 65° latitude.