// Astro helpers + city list
// Extracted as-is from clock-lille.html

export const CITIES = [
  { label: 'LIL', lon: 3.067, lat: 50.63 },
  { label: 'TYO', lon: 139.69, lat: 35.68 },
  { label: 'NYC', lon: -74.006, lat: 40.71 },
]

export function solarDeclination(doy) {
  return (-23.45 * Math.cos((2 * Math.PI / 365) * (doy + 10)) * Math.PI) / 180
}

export function dayOfYear(d) {
  return Math.floor((d - new Date(d.getFullYear(), 0, 0)) / 86400000)
}