jCalendar syntax highlighting#

The extension also registers jcal (and jcalendar) as language aliases that apply JSON highlighting to raw jCal snippets without triggering the calendar rendering:

.. code-block:: jcal

    ["vcalendar",
      [["version", {}, "text", "2.0"]],
      [["vevent",
        [
          ["summary",  {}, "text",      "Quarterly review"],
          ["dtstart",  {}, "date-time", "2026-04-01T09:00:00Z"],
          ["dtend",    {}, "date-time", "2026-04-01T10:00:00Z"]
        ], []
      ]]
    ]

The result is a static, JSON-highlighted code block:

["vcalendar",
  [["version", {}, "text", "2.0"]],
  [["vevent",
    [
      ["summary",  {}, "text",      "Quarterly review"],
      ["dtstart",  {}, "date-time", "2026-04-01T09:00:00Z"],
      ["dtend",    {}, "date-time", "2026-04-01T10:00:00Z"]
    ], []
  ]]
]

The highlighting is provided by Pygments’ built-in JSON lexer.

Options#

jcal supports the linenos and emphasize-lines options, just like any other .. code-block:: language:

.. code-block:: jcal
   :linenos:
   :emphasize-lines: 5, 6

 1 ["vcalendar",
 2   [["version", {}, "text", "2.0"]],
 3   [["vevent",
 4     [
 5       ["summary",  {}, "text",      "Quarterly review"],
 6       ["dtstart",  {}, "date-time", "2026-04-01T09:00:00Z"],
 7       ["dtend",    {}, "date-time", "2026-04-01T10:00:00Z"]
 8     ], []
 9   ]]
10 ]