code: def compute_all_minutes(opens_in_ns, closes_in_ns):
      
      deltas = closes_in_ns - opens_in_ns
  
      # + 1 because we want 390 mins per standard day, not 389
      daily_sizes = (deltas // NANOSECONDS_PER_MINUTE) + 1
      num_minutes = daily_sizes.sum()
  
      # One allocation for the entire thing. This assumes that each day
      # represents a contiguous block of minutes.
      pieces = []
  
      for open_, size in zip(opens_in_ns, daily_sizes):
          pieces.append(
              np.arange(open_,
                        open_ + size * NANOSECONDS_PER_MINUTE,
                        NANOSECONDS_PER_MINUTE)
          )
  
      out = np.concatenate(pieces).view('datetime64[ns]')
      assert len(out) == num_minutes
      return out
docs: Given arrays of opens and closes, both in nanoseconds,
      return an array of each minute between the opens and closes.