GeologicTime.jl is mainly designed to draw geologic time scale in a certain time interval using the function drawtimescale. This function relies on PyPlot.jl, which needs to be manually installed and imported.

using GeologicTime
using PyPlot
figure(figsize=(5.4, 0.45))
drawtimescale(100, 0, [3, 4]; fontsize=8, texts = Dict(
	"Cretaceous" => "Cretaceous", "Paleogene" => "Paleogene", 
	"Neogene" => "Neogene", "Quaternary" => "Q", 
	"Late Cretaceous" => "Late Cretaceous", "Paleocene" => "Paleoc.", 
	"Eocene" => "Eocene", "Oligocene" => "Oligoc.", "Miocene" => "Miocene", 
	"Pliocene" => "P", "Pleistocene" => "P"))
gca().set_position([0.02, 0.05, 0.96, 0.9])
savefig("timescale.png", dpi=300)

The code above generates the following image. In the argument list of drawtimescale, 100 and 0 are two ends of the time interval, representing time in million year ago; [3, 4] indicates the function to draw periods (code 3) and epochs (code 4) in the chart.

In addition, the package also provides simple lookup functions such as getunit, getcolor, getstart, getstop, getspan, and getgeotime, whose usage is explained in the documentation. These functions do not rely on PyPlot.jl --- they can be called once GeologicTime.jl is loaded.

Code and documentation of GeologicTime.jl are released under the MIT License. However, all the data are based on materials from Wikipedia accessed on April 23, 2023, available under the CC-SA 3.0 License. Credit of relevant files including data/wikipedia.html and its derivation data/timescale.tsv is due to Wikipedia contributors.