# stamp.ludic - the ISO time an event happened, written from the wall clock's seconds with the date
# worked out in whole numbers (days from the civil calendar), not a string built by DateTime
function tj_stamp(sb: StrBuf, secs: int) -> void {
  var days = secs / 86400
  var rem = secs % 86400
  if rem < 0 {
    rem += 86400
    days -= 1
  }
  let z = days + 719468
  var era = z / 146097
  if z < 0 { era = (z - 146096) / 146097 }
  let doe = z - era * 146097
  let yoe = (doe - doe / 1460 + doe / 36524 - doe / 146096) / 365
  let doy = doe - (365 * yoe + yoe / 4 - yoe / 100)
  let mp = (5 * doy + 2) / 153
  let d = doy - (153 * mp + 2) / 5 + 1
  var m = mp + 3
  if mp >= 10 { m = mp - 9 }
  var y = yoe + era * 400
  if m <= 2 { y += 1 }
  sb_byte(sb, 34)
  sb_int(sb, y)
  sb_byte(sb, 45)
  sb_int2(sb, m)
  sb_byte(sb, 45)
  sb_int2(sb, d)
  sb_byte(sb, 84)
  sb_int2(sb, rem / 3600)
  sb_byte(sb, 58)
  sb_int2(sb, (rem / 60) % 60)
  sb_byte(sb, 58)
  sb_int2(sb, rem % 60)
  sb_add(sb, "Z\"")
}