ical

Display the current month's calendar

$ ical

$ ical --gregorian [yyyymmdd]

$ ical --hijri [yyyymmdd]

No direct synopsis for a standard `ical` command exists.
Interaction with iCalendar data on Linux typically involves specialized command-line tools, each with its own syntax and capabilities. Users would invoke specific commands for calendar clients or synchronization tools, such as:

khal [OPTIONS] [COMMAND] [ARGUMENTS]

calcurse [OPTIONS]

vdirsyncer [COMMAND] [OPTIONS]
These commands are designed to interact with iCalendar data and often provide functionalities like viewing events, adding new ones, or synchronizing with remote calendars.

-f <file>
    Specify an iCalendar (`.ics`) file for processing (common in parsing tools).

-s <source>
    Specify a calendar source, often a local directory or remote URL (common in calendar clients).

--date <date>
    Filter or operate on events for a specific date or date range (common in viewing tools).

--add
    Initiate adding a new event or task (common in interactive calendar clients).

--sync
    Synchronize local calendar data with a remote server (common in synchronization tools).

--list
    Display a list of events or tasks (common in viewing tools).

The name `ical` refers primarily to the iCalendar format (files typically ending in `.ics`), which is a widely used standard for exchanging calendaring and scheduling information. Contrary to what its name might suggest, `ical` is not a standard, widely-distributed command-line utility found in most Linux distributions. Users often search for an `ical` command expecting a direct tool to view, create, or manage calendar events from the terminal using this format. Instead, interacting with iCalendar data on Linux typically involves a variety of specialized command-line calendar clients, synchronization tools, or scripting solutions that parse and manipulate `.ics` files. These tools offer functionalities ranging from simple event display to complex synchronization with remote calendar servers.

The most significant caveat is that `ical` is not a standard Linux command. Users looking for direct `ical` functionality should instead explore existing command-line calendar clients (like `khal`, `calcurse`) or synchronization utilities (`vdirsyncer`), or consider scripting with iCalendar parsing libraries available in languages like Python.

The iCalendar format is a plain text file format for calendaring and scheduling data. It defines a set of properties for events (VEVENT), to-dos (VTODO), journal entries (VJOURNAL), and free/busy time (VFREEBUSY). These properties include details like summary, location, start/end times, recurrence rules, and alarms. Files using this format typically have the `.ics` extension.

On Linux, interacting with iCalendar data often involves:
1. Dedicated CLI Calendar Clients: Tools like khal or calcurse provide a full-fledged terminal interface for managing calendars.
2. Synchronization Tools: Utilities like vdirsyncer synchronize local iCalendar files with remote CalDAV servers.
3. Scripting: Using programming language libraries (e.g., Python's icalendar) to parse, generate, or manipulate .ics files programmatically.

The `ical` designation most directly relates to the iCalendar standard (RFC 5545, formerly RFC 2445), developed by the Internet Engineering Task Force (IETF). This format gained prominence in the late 1990s as a vendor-neutral way to exchange calendar data. While the format became ubiquitous, a single, universal `ical` command-line tool did not emerge as a standard part of Linux distributions. Instead, various open-source projects developed independent command-line clients and libraries to interact with iCalendar data, driven by the need for terminal-based productivity and synchronization capabilities.

cal(1), khal, calcurse, vdirsyncer