def time()

in atlas-chart/src/main/scala/com/netflix/atlas/chart/graphics/Ticks.scala [584:626]
36 lines of code
15 McCabe index (conditional complexity)

  def time(s: Long, e: Long, zone: ZoneId, n: Int): List[TimeTick] = {

    // To keep even placement of major grid lines the shift amount for the timezone is computed
    // based on the start. If there is a change such as DST during the interval, then labels
    // after the change may be on less significant boundaries.
    val shift = zone.getRules.getOffset(Instant.ofEpochMilli(s)).getTotalSeconds * 1000L

    val dur = e - s
    val candidates = timeTickSizes.filter(t => dur / t._1 <= n)
    if (candidates.nonEmpty) {
      val (major, minor) = candidates.head
      val ticks = List.newBuilder[TimeTick]

      val zs = s + shift
      val ze = e + shift
      var pos = zs / major * major
      while (pos <= ze) {
        if (pos >= zs) ticks += TimeTick(pos - shift, zone, pos % major == 0L)
        pos += minor
      }
      ticks.result()
    } else {
      val start = LocalDateTime.ofInstant(Instant.ofEpochMilli(s), zone).toLocalDate
      val end = LocalDateTime.ofInstant(Instant.ofEpochMilli(e), zone).toLocalDate
      val days = dur / (24 * 60 * 60 * 1000L)
      val (amount, unit, fmt) = days match {
        case d if d <= n       => (1L, ChronoUnit.DAYS, defaultTimeFmt)
        case d if d / 30 <= n  => (1L, ChronoUnit.MONTHS, monthTimeFmt)
        case d if d / 90 <= n  => (3L, ChronoUnit.MONTHS, monthTimeFmt)
        case d if d / 365 <= n => (1L, ChronoUnit.YEARS, yearTimeFmt)
        case d                 => (d / (n * 365), ChronoUnit.YEARS, yearTimeFmt)
      }

      val ticks = List.newBuilder[TimeTick]
      var t = start
      while (t.isBefore(end) || t.isEqual(end)) {
        val timestamp = t.atStartOfDay().toInstant(ZoneOffset.UTC).toEpochMilli - shift
        ticks += TimeTick(timestamp, zone, formatter = Some(fmt))
        t = t.plus(amount, unit)
      }
      ticks.result()
    }
  }