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- 7-12 Saturda 4:21 21:38 41.6 21.90 -5.7 6.71 44.1
13 Sunday 4:22 21:37 41.4 21.75 -5.8 6.75 43.8
14 Monday 4:23 21:36 41.2 21.60 -6.0 6.79 43.5
Average for 3 days
from 3 values is 4:22 21:37 41.4 21.75 -5.8 6.75 43.8
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 d12.07.2025 t09:41 l16.6 f49.2 ut2 h-6 n2 i1