Port of the circadian.el plugin I like so much in Emacs

This plugin changes automatically between 2 themes according to the sunrise and sunset times at your location. It literally uses an astronomical formula to obtain the hours from the current date, the latitude, and the longitude in order to set the colorschemes correctly for you.

• Add option to make plugin silent

No configuration option is mandatory. Calling the setup function will set the colorscheme according to the time of day, if the relevant option (day or night) is filled.

require('circadian').setup({
  -- Latitude: Defaults to Paris' latitude
  lat = 0.0,
  -- Longitude: Defaults to Paris' longitude
  lon = 0.0,
  -- Stop notifying on event
  silent = false,
  -- Day theme: the background is optional, but useful for themes that
  -- control light/dark variants with it. Defaults to nil everywhere
  -- (will not change a thing when Sun rises)
  day = { background = "light", colorscheme = "alabaster" },
  -- Night theme: the background is optional, but useful for themes that
  -- control light/dark variants with it. Defaults to nil everywhere
  -- (will not change a thing when Sun sets)
  night = { background = "dark", colorscheme = "catpuccin" },
  night_callback = function end,
  day_callback = function end,
})

Totally unrelated, but Circadian is a little noisy on the log side, so using something like nvim-notify or any other vim.notify handler is going to feel good.

• I don't know how it works with all the themes that are full lua and need a setup() function call with options
• I don't know how robust the algorithm is when switching between day and night (especially if you have a neovim started at night until the next sunrise)
• Probably a bunch of other things are going to fail