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- 9-20 Saturda 6: 6 19:28 32.0 0.90 6.6 10.63 8.4
21 Sunday 6: 7 19:26 32.0 0.51 7.0 10.69 7.8
22 Monday 6: 9 19:24 31.9 0.12 7.3 10.75 7.2
Average for 3 days
from 3 values is 6: 7 19:26 32.0 0.51 7.0 10.69 7.8
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 d20.09.2025 t12:44 l16.6 f49.2 ut2 h-6 n2 i1