calendar(options)

This returns a tree structure representing years, months, and days from a start date to an end date. This is useful, for example, in generating a portion of a site that presents information for a given year, month, or day.

The options determines the result through the following properties:

• startDate: a date provided as a string in “YYYY-MM-DD”, “YYYY-MM”, or “YYYY” format. If a start year is provided, but a month is not, then the first month of the year will be used. If a start month is provided without a day, the first day of that month will be used. Default value: today.
• endDate: a date in the same formats as startDate. If an end year is provided by a month is not, the last month of the year will be used. If an end month is provided without a day, the last day of that month will be used. Default value: today.
• value: a function that accepts (year, month, day) parameters. This is required.

Example: A site wants to define year/month/day routes for a given time range. For brevity, this will just be the week from 2025-02-26 to 2025-03-04. These routes can be defined as:

// calendar.ori
calendar({
  start: "2025-02-26"
  end: "2025-03-04"
  value: (year, month, day) => `Page for ${ year }-${ month }-${ day }`
})

This produces a skeleton calendar tree with the years, months, and days for that time range:

$ ori calendar.ori/
"2025":
  "02":
    "26": Page for 2025-02-26
    "27": Page for 2025-02-27
    "28": Page for 2025-02-28
  "03":
    "01": Page for 2025-03-01
    "02": Page for 2025-03-02
    "03": Page for 2025-03-03
    "04": Page for 2025-03-04

When served, this would allow someone to browse to the page for a given date using a route like /2025/03/03.