§ Mr. Norris
At Heathrow, the night quota period runs from 2330 to 0600. In the 1994 summer season—27 March 1994 to 23 October 1994—there were 3,204 runway movements in the night quota period, of which 2,905 counted against the movements limit, an average of 15 per night. Data for times outside the night quota period are not readily available on an equivalent basis. Very few movements are scheduled for the period 2300 to 2329, but actual numbers of movements in this period fluctuate considerably per night depending on whether flights have been delayed from earlier in the day. Movements in the period 0601 to 0630 are mostly arrivals. Analysis of data for sample weeks during the summer shows an average of about 16 movements per night during this half hour. There can be considerable variation in the number of movements in the half hours immediately before and after 0600 on a particular night due to the weather.