Length of the Night
as an interval between the PM and AM moments
of Sun passing a given angular height (default -6°, for the ``civil night''):
The centre of Sun is at a place with coordinates [Lambda=16.6°, Phi=49.2°]
in an angular height of h =-6.0°
in the following morning and evening moments (given in UTC+ 2h):
year-month-day morning evening twilight decl. >mean night A-W
h:min / 1 min /1° /1min /1h /1°
2025- 4- 5 Saturda 5:49 20: 3 32.8 6.26 -2.7 9.77 16.8
6 Sunday 5:47 20: 5 32.9 6.64 -2.4 9.70 17.4
7 Monday 5:45 20: 6 33.0 7.02 -2.1 9.64 18.0
Average for 3 days
from 3 values is 5:47 20: 5 32.9 6.64 -2.4 9.70 17.4
Meaning of remaining columns:
Twilight is an interval to/from h=-0.8°
Declination of Sun is given for the moment of local mean noon,
>Mean says how much is the Sun ahead of the mean time,
Night is the time the Sun travels below h,
A-W is departure of solar azimuth from the west when at h afternoon.
This is a result of the programme
nights (available as a part of a package
pas_jh.zip (1.2 MB) --
the needed Pascal units themselves are unzipped within
this directory, the whole tree of my programmes within
this directory)
with a command line:
nights d05.04.2025 t10:05 l16.6 f49.2 ut2 h-6 n2 i1