A timeline typst package

This package uses cetz to
provide a interface in typst for making timelines, inspired
by the latex chronology package.

It provides the following to work with timelines.

• A event and eventspan object for grouping data
  you want displayed on the timeline.
• The timeline function itself.

For getting started quickly add the following to your document:

#import "@preview/herodot:1.0.0" : * 

See the visual examples below and some examples at the end of the readme
for what fields and options the package offers. The source for the examples
can be found at examples/example.typ.

Example

A basic example of using the timeline with the event and eventspan
constructor without setting any of the optional style settings.

#import "@preview/herodot:1.0.0" : * 

#let scifi-time = timeline(
  interval: 200,
  startyear: -200,
  endyear: 1000,
  events: (
  
    // basic event with only title and year
    event(
      title: "Alien invasion",
      year: 0
    ),

    // event with title and the exact date
    event(
      title: "First alien-human marriage",
      year: 40,
      month: 3,
      day: 20,
    ) 
  ),
  eventspans: (
    eventspan(
      title: "Climate collaps",
      start-point: -100,
      end-point: -30
    ),
    eventspan(
      title: "Integration of Earth into galatic commerce",
      start-point: 10,
      end-point: 70
    ),
  ),
)

#scifi-time

Properties/fields

The settable properties for customizing the look
of the timeline. Visual examples can be seen in
the example.pdf

event

The base obligatory settings for event is the year and title.

Property	Description
title	The title of the event, as a string
year	The year of the event, as an integer

Herodot however also has support for setting exact date of the
event with the month and day fields.

Property	Description
month	The month represented as an integer (1-12)
day	The day as an integer (1-31)

eventspan

Obligatory fields for an eventspan.

Property	Description
title	Title of the event
start-point	It's starting point as an integer
end-point	It's end-point as an integer
spanheight	height/width of the eventspan (the same distance on both sides of the timeline)
spanheight-positive-y	Alternative height/width of the eventspan above the timeline (allows for alternative heights between the distance above and below the timeline)
spanheight-negative-y	Alternative height/width of the eventspan below the timeline (allows for alternative heights between the distance above and below the timeline)

See the optional styling properties for location
and color setting of the eventspan under timeline.

timeline

Property	Description
startyear	The start year for the timeline, can be a postive or negative integer
endyear	The last year of the timeline, can also be either a positive or negative integer
interval	Interval between years to be marked on the timeline
events	Array of events to put on the timeline
eventspans	Array of eventspans to put on the timeline
event-rotation	The rotation of the text title of events (default: 45deg)
span-rotation	The rotation of the text title of eventspans (default: 0deg)
event-display	The date information displayed along the event title, the default is year, but i can be either one of day/month/year/day-month, day-month-year or none.
month-locale	The string locale of the months to be used to display it, by default english, but an array of strings can be manually passed to override it and used alternatively.

Optional styling properties	Description
length-of-timeline	Length of timeline in cm
linestroke	The width and color of the lines making up the timeline