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Command line utility providing access to the Roman Catholic liturgical calendar (post-Vatican II).

Built on top of the calendarium-romanum Ruby gem.


calrom is a Ruby gem:

$ gem install calrom


Specifying date range

Print liturgical calendar for the current month (default):

$ calrom

... for a specified month of the current year:

$ calrom -m 9

... for a specified month of another year:

$ calrom -m 1 2028 or $ calrom 1 2028

... for a whole year:

$ calrom 2017

... for the current year:

$ calrom -y

... for a specified date:

$ calrom 2028-01-15

... for an arbitrary date range:

$ calrom 2028-01-15 2028-03-07

Selecting calendar

There are a few calendars bundled in calrom (actually in the calendarium-romanum gem) and ready to use. List them:

$ calrom --calendars

Each entry of the listing contains an ID of the calendar, it's name and language code. Use calendar ID to request General Roman Calendar in Latin:

$ calrom --calendar=universal-la

You can prepare your own calendar data and load them:

$ calrom --calendar=path/to/my_calendar.txt

If you specify more than one calendar, they are loaded "layered" one over another (from left to right), which comes in handy when extending a general calendar with just a few additional and/or differing celebrations, e.g. solemnities (titular, dedication) of the local church:

$ calrom --calendar=universal-la --calendar=path/to/our_local_celebrations.txt

Data presentation settings

Print detailed listing:

$ calrom -l

Disable colours:

$ calrom --no-color

Machine-readable output formats:

$ calrom --format=json - prints JSON array containing one object per day. The object contents mimick output of the Church Calendar API v0.

$ calrom --format=csv - prints a CSV, one celebration per line (i.e. there is one or more lines for each liturgical day).

Configuration files

calrom looks for configuration files /etc/calromrc and ~/.calromrc. They are processed in this order and both are used if available. Their syntax is that of shell options and arguments (with the sole exception that newline is not considered end of shell input, but generic whitespace), supported are all options and arguments accepted by the command. It usually makes sense to use configuration files only for the most fundamental settings you will never change, like selecting calendar (if you know you will always check this single one) or disabling colours (if you hate colourful output).

If a custom configuration file location is specified on the command line, $ calrom --config=path/to/my/custom/config, the standard system-wide and user-specific configuration files are not loaded.

Example configuration file, loading the proper calendar of the archdiocese of Prague and disabling colours:

# shell-like comments can be used in configuration files

--calendar=czech-cs       # celebrations common for the whole Czech Republic
--calendar=czech-cechy-cs # Bohemia
--calendar=czech-praha-cs # archdiocese of Prague
--calendar=/home/igneus/calendar_data/local_church.txt # path to a custom calendar file with proper celebrations of the parish where I live (titular feast of the church, dedication)

--no-color # disable colours

(Configuration file format is inspired by .rspec.)

Running tests

Clone the repository, $ bundle install to install dependencies, then:

$ rake cucumber - run specs describing the command line interface

$ rake spec - run specs describing internal implementation details

$ rake - run all groups of specs one after another

Project roadmap

  • [x] detailed listing of a day/month/year/range of dates
  • [ ] month/year overview - options and output mostly mimicking the BSD Unix cal utility, but with liturgical colours and celebration ranks
  • [ ] condensed format (but with detailed information) suitable for awesome/i3 toolbars etc.
  • [x] machine-readable detailed listing
  • [ ] year summary: lectionary cycles, movable feasts
  • [x] configuration file to set default options
  • [x] specify calendar data path (with support for layering several calendars)
  • [ ] option to auto-select one of optional celebrations - with multiple supported strategies (prefer ferial, take first non-ferial, configured whitelist, blacklist)
  • [ ] integrate online data sources
  • [ ] interactive browsing

Backward compatibility

Project adheres to semantic versioning with regard to the command line interface: between major releases, the same configuration (through command line options and other ways of configuration the application will eventually support) should print information of the same (or greater) level of detail for the same range of dates. For output formats explicitly documented as machine-readable, format must be preserved (where some machine-readable formats, especially the structured ones, allow backward-compatible extensions, others do not, according to their nature).

No backward compatibility is guaranteed on the level of the application's internal interfaces, since they are not intended to be used by third-party code.

CLI patterns

When designing new elements (options, arguments) of the command line interface


GNU/GPL 3.0 or later