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- 7-22 Tuesday 4:34 21:26 39.8 20.17 -6.5 7.12 40.7
23 Wednesd 4:35 21:25 39.6 19.97 -6.6 7.17 40.3
24 Thursda 4:37 21:24 39.4 19.76 -6.6 7.22 39.9
Average for 3 days
from 3 values is 4:35 21:25 39.6 19.96 -6.6 7.17 40.3
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 d22.07.2025 t21:01 l16.6 f49.2 ut2 h-6 n2 i1