THIS is apropos of letters by Capt Sohail Sultan and Khawaja Fariduddin (Nov 5).

Our normal PST is already about half an hour ahead of its geographical time zone, and advancing it a further one hour puts it one-and-a-half hours ahead.

Pakistan 's mean longitude is about 70 degrees E, which corresponds to a zone time of four-and-a-half hours ahead of GMT (to the nearest half hour) against our normal PST of +5 GMT.

For the benefit of the layman, the global circumference of 360 degrees in longitude is divided into 24 time zones of 150 degrees each, i.e. 360 degrees/24 = 150.

The one hour advanced DST puts our midday, when the sun is at the highest point, midway between sunrise and sunset (or Zuhar) at about 1.30pm instead of the normal 12 noon.

Under normal PST in offices, on Fridays there is a reasonable extension of the lunch break for prayers, but with DST most of the working afternoon is lost due to the very late prayer timings.

In mid-summer, sunset is about 8.15pm, very late, and towards the end of November sunrise is well after 7am, due to which children rise and board their school bus in complete darkness.

The mean longitude of India and Sri Lanka is about 80 degrees E, and they maintain their standard time as +5.30 on GMT, which corresponds to their geographical zone time.

Similarly Bangladesh, with a mean longitude of about 90 degrees E, maintains +6 on GMT, also corresponding.

Can we be a little more sensible on the application of DST?

RAFI AHMED
Karachi