Times when hour and minute hands are 90 degrees

time_data.ts

function pad(num: number) {
  return `0000${num}`.slice(-2)
}
function time(hour: number) {
  return new Date(
    `Tue Aug 08 2023 ${pad(hour)}:00:00 GMT+0200 (Central European Summer Time)`
  )
}

const times = [
  //minute hand has to move 90° back and forward to get 90° angle given hour does not move
  [12, -90, 90], 
  [1, -60, 120],
  [2, -30, 150],
  [3, 0, 0],
  [4, 30, 210],
  [5, 60, 240],
  [6, -90, 90],
  [7, -60, 120],
  [8, -30, 150],
  [9, 0, 0],
  [10, 30, -150],
  [11, 60, -120],
].map(([hour, before, after]: number[]) => {
  const back = (before / 5.5) * 60000
  const forward = (after / 5.5) * 60000
  const current = time(hour)
  return {
    forward: new Date(current.getTime() + forward).toString(),
    back: new Date(current.getTime() + back).toString(),
  }
})

console.log(times)