A DateTime
should really be treated as a TimeSpan
which is taken as the difference from a standard reference point (like Jan 1, 1970). Something like that:
// 2024
const y2024 = { year: 2024 } | { thousand: 2, year: 24 }
// 2000BCE = -2000 - 1970
const y2000bce = { year: -3970 }
// 13.8bya
const t13_8bya = { billion: -13, million: -8 }