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CALCELESTIAL

Section: User Commands (1)
Updated: May 2013
Index
 

NAME

calcelestial - calculates positions, rise, set and transit times of celestial bodies  

DESCRIPTION

Together with tools like 'at', 'cron' and 'date' it can be used to schedule arbitrary tasks at planet and moon rise, set or transit times.  

SYNOPSIS

calcelestial -p [object] -q [location] -m [moment] -f [format]  

OPTIONS

-p, --object
available objects are:
sun
moon
mars
neptune
jupiter
mercury
uranus
saturn
venus
pluto
-H, --horizon
calc rise/set time with twilight: nautic, civil or astronomical
-t, --time
calc at given time: YYYY-MM-DD [HH:MM:SS]
-m, --moment
calc position at moment of: rise, set, transit
-n, --next
use rise, set, transit time of tomorrow
-f, --format
output format: see strftime(3) and FORMAT section below for more details
-a, --lat
geographical latitude of observer: -90 to 90deg
-o, --lon
geographical longitude of oberserver: -180 to 180deg
-q, --query
query geonames.org for geographical coordinates
-z, --timezone
override system timezone
-u, --universal
use universial time for parsing and formatting
-h, --help
show this help
-v, --version
show version

 

FORMAT

calcelestial supports all conversion specifications as documented in strftime(3).
additionally these special specifiers have been added:
%J
Julian Date
§r
equatorial right ascension in degrees
§d
equatorial declination in degrees
§a
azimut in degrees from north
§h
altitude in degrees
§d
diameter in arcseconds
§e
distance in kilometer
§t
observer timezone in hours west
§A
observer latitude in degrees north
§O
observer longitude in degrees east
§s
azimuth direction as letter,
§§
A literal '§' character
 

NOTES

A combination of --lat & --lon or --query is required.

The argument -q, --query fetches coordinates from the geonames.org database. Fetched coordinates will be cached locally. So an active internet connection is only required for the first time. Please be aware of possible privacy issues!

When symlinking the calcelestial binary to 'sun', 'moon' etc., the argument -p, --object is negligible:

sun -m rise -q Aachen
 

EXAMPLES

echo "~/bin/enable-lightning" | at $(calcelestial -p sun -m set -q Frankfurt -H civil)
enable lightning at sunset in Frankfurt
shutdown $(date -d "+10min $(calcelestial -m transit -a 50.55 -o -6.2)" +%H:%M)
shutdown system 10 minutes after solar noon in Berlin
nvram-wakeup -s $(date -d "-10min $(calcelestial -m rise -q Aachen)" +%s)
start system 10 minutes before sunrise in Aachen
 

FILES

geonames.org queries will be cached in ~/.geonames.cache  

AUTHOR

calcelestial is written by Steffen Vogel <post@steffenvogel.de>  

BUGS

%s formatstring has buggy timezone offset in conjunction with daylight savings


 

Index

NAME
DESCRIPTION
SYNOPSIS
OPTIONS
FORMAT
NOTES
EXAMPLES
FILES
AUTHOR
BUGS

projects/calcelestial.txt · Last modified: 01:32 05.05.2013 by Steffen Vogel