kosmorro

Get ephemerides for Paris, France

$ kosmorro [[-la|--latitude]] 48.7996 [[-lo|--longitude]] 2.3511

$ kosmorro [[-la|--latitude]] 48.7996 [[-lo|--longitude]] 2.3511 [[-t|--timezone]] 2

$ kosmorro [[-la|--latitude]] 48.7996 [[-lo|--longitude]] 2.3511 [[-d|--date]] 2020-06-09

$ kosmorro [[-f|--format]] pdf [[-o|--output]] [path/to/file.pdf]

kosmorro [OPTIONS] [<YYYY-MM-DD>]

-h, --help
    Print help information

-V, --version
    Print version information

-c, --config <PATH>
    Path to custom config file

-l, --latitude <LAT>
    Observer latitude in decimal degrees (e.g., 48.8566)

-g, --longitude <LON>
    Observer longitude in decimal degrees (e.g., 2.3522)

-z, --timezone <TZ>
    Observer timezone (IANA name, e.g., Europe/Paris)

-d, --date <DATE>
    Target date (YYYY-MM-DD, relative like '+1M', or omit for today)

-o, --output <FILE>
    Output file path (auto-detects format: .txt, .html, .ics)

--stdout
    Force output to stdout instead of file

--quiet
    Suppress non-error output

--verbose
    Enable verbose logging

Kosmorro is a powerful command-line tool for generating richly formatted astronomical calendars, or ephemerides, tailored to your location on Earth.

It computes and displays events such as moon phases, planetary risings and settings, sunrise/sunset times, meridian transits, conjunctions, and more for the Sun, Moon, and major planets (Mercury to Neptune).

Calendars are rendered in your terminal with colors and Unicode symbols for readability, or exported to files in plain text, HTML, or iCalendar (.ics) formats for use in calendar apps.

Computations use the precise VSOP87 planetary theory and are fully offline—no internet required. Location is specified via latitude/longitude/timezone, with defaults from a config file.

Ideal for astronomers, educators, or anyone wanting daily sky event overviews. Supports single dates or full months/years.

Requires valid location data (lat/lon/tz); defaults from ~/.config/kosmorro/config.toml if unspecified.
High-precision computations may be slow for full years on low-end hardware.
Not suitable for real-time telescope pointing.

Default: ~/.config/kosmorro/config.toml
Example:
latitude = 48.8566
longitude = 2.3522
timezone = "Europe/Paris"

kosmorro 2024-12-21 # Winter solstice events
kosmorro -o output.html 2024 # Full year HTML calendar
kosmorro --stdout -d '+1w' > week.ics # Next week iCal

Developed by Pierre Fernandez (KiboZE) starting 2020.
Initial release v0.1.0; current stable v5.x (2024).
Hosted on GitLab; rewritten in Rust for performance.

cal(1), gcal(1)