# How do you calculate daylight hours?

## How do you calculate daylight hours?

Letting t be the day of the year (from 1 to 365), you can figure the number of hours of sunlight, H, if you enter a value for t in the equation H(t) = 2.4 sin (0.017t – 1.377) + 12. The following figure shows the graph of this equation. The number of hours of sunlight, H, in San Diego on Day t.

**How many hours of daylight does Germany have?**

With almost 17 hours, the longest days are in June. The sunset is then only at 21:33 o’clock, whereby it can be depending upon weather conditions still another hour somewhat brightly….Sunrise and sunset in the most important cities of Germany.

City | Wuppertal |
---|---|

Sunrise | 06:41 am |

Sunset | 08:21 pm |

Hours of daylight | 13:40 h |

### How many hours of daylight are there in summer?

The benefit of long days in summer always being matched by long periods of darkness in winter: 18 hours of daylight in midsummer; only six and a half hours in midwinter. While the 23.5° tilt is pretty much fixed, the earth’s orbit around the sun is far from a perfect circle.

**Why is there more daylight at the end of the day?**

As the earth is roughly symmetrical in shape the longer period of daylight is split also roughly between a) more daylight at the beginning of the day, matched by b) more daylight at the end of the day. However the two are not matched exactly because of: a) the axial tilt of the earth, and especially b) its eccentric orbit around the sun.

## How many hours of daylight is there in midwinter?

At high latitudes however, such as at Inverness in northern Scotland, the difference is more like 12 hours between midwinter and midsummer. The benefit of long days in summer always being matched by long periods of darkness in winter: 18 hours of daylight in midsummer; only six and a half hours in midwinter.

**How to calculate the length of the day?**

The following tables provide year-round hours of daylight at 5 degree intervals from 60°N to 60°S latitude for every 15 day period. Shing Lam compiled the C code based on a formula published in: Meeus, Jean. (1991) Astronomical algorithms. Richmond, Va.: Willmann-Bell. ISBN 0943396352 We reorganized the data into these tables. Choose a Latitude: