Calculate sunrise and sunset times for the current or targetted day.
The times can be adjusted either for twilight or fixed durations.
The program can either: wait for sunrise or sunset (function: wait),
or return the time (GMT or local) the event occurs (function: list),
or report the day length and twilight timings (function: report),
or simply report if it is DAY or NIGHT (function: poll).
You should specify the latitude and longitude of your target location.
Major options, either:
poll Returns immediately indicating DAY or NIGHT. See 'program exit codes'. Default.
wait Sleep until specified event occurs. Else exit immediate.
list [X] Report twilight times for next 'X' days (inclusive). Default: 1.
report Generate a report about the days sunrise and sunset timings.
Minor options, any of:
[no]debug Print extra info and returns in one minute. Default: nodebug.
[no]version Print the version number. Default: noversion.
[no]help Print this help. Default: nohelp.
[no]gmt Print times in GMT or local-time. Default: nogmt.
Twilight types, either:
daylight Top of sun just below the horizon. Default.
civil Civil Twilight. -6 degrees below horizon.
nautical Nautical twilight. -12 degrees below horizon.
astronomical Astronomical twilight. -18 degrees below horizon.
angle [X.XX] User-specified twilight-angle (degrees). Default: 0.
Sunrise/sunset. Only useful with major-options: 'wait' and 'list'. Any of: (default: both)
rise Wait for the sun to rise past specified twilight & offset.
set Wait for the sun to set past specified twilight & offset.
offset [MM|HH:MM] Time interval (+ve towards noon) to adjust twilight calculation.
Target date. Only useful with major-options: 'report' or 'list'. Default: today
d [DD] Set the target Day-of-Month to calculate for. 1 to 31.
m [MM] Set the target Month to calculate for. 1 to 12.
y [YYYY] Set the target Year to calculate for. 2000 to 2099.
latitude/longitude coordinates: floating-point degrees, with [NESW] appended. Default: Bingham, England.
Exit (return) codes:
0 OK: exit from 'wait' or 'list' only.
2 Exit from 'poll': it is DAY or twilight.
3 Exit from 'poll': it is NIGHT (after twilight).
Example 1: sunwait wait rise offset -1:15:10 51.477932N 0.000000E
Wait until 1 hour 15 minutes 10 secs before the sun rises in Greenwich, London.
Example 2: sunwait list 7 civil 55.752163N 37.617524E
List civil sunrise and sunset times for today and next 6 days. Moscow.
Example 3: sunwait poll exit angle 10 54.897786N -1.517536E
Indicate by program exit-code if is Day or Night using a custom twilight angle of 10 degrees above horizon. Washington, UK.
Example 4: sunwait list 7 gmt sunrise angle 3
List next 7 days sunrise times, custom +3 degree twilight angle, default location.
Uses GMT; as any change in daylight saving over the specified period is not considered.
Note that program uses C library functions to determine time and localtime.
Error for timings are estimated at: +/- 4 minutes.
For versions of Ubuntu between 14.04 LTS (Trusty Tahr) and 15.10 (Wily Werewolf), as well as Ubuntu flavours that don’t include snap by default, snap can be installed from the Ubuntu Software Centre by searching for snapd.
Alternatively, snapd can be installed from the command line:
sudo apt update
sudo apt install snapd
Either log out and back in again, or restart your system, to ensure snap’s paths are updated correctly.
To install Sunwait, simply use the following command: