(a) (i) Characteristics of Time Zone: - refers to a region where the same standard time is used - spans 15º of longitude-there are 24 time zones in all - each has its own standard time - time difference between 2 adjacent time zones is 1 hour - local time is determined by the central meridian within the zone longitude O° is the reference point for all time zones - time zones east of GMT are ahead in tme - time zones west of GMT are behind in time -west and east time zones are separated by the IDL - demarcating lines are not so straight areas with large longitudinal stretch have more than one time zone.
(ii) Characteristics of International Date Line: - it is at the 180° meridian - an imaginary line - located half way round the world from the Prime Meridian passes through the Mid-Pacific Ocean - it avoids cutting through oceanic islands and countries - the longitude which marks the difference in the day/time - a day is gained when it is crossed to the east - a day is lost when it is crossed to the west- it joins the Prime Meridian to form a Great Circle.
(b) Calculation of longitude of Town B: - longitude of Town A = 30º W - time in Town A =9.00am = 9 hours time in Town B = 6.00pn = 18 hours - longitude of Town B = ? - 15° of longitude is = 1 hour - Difference in time between towns B and A is 18 hours - 9 hours - Difference in Longitude = 9 hours x 15º - = 135 - Time of town B is 6.00pm which is ahead of Town A - Therefore, Town B is to the east of Town A-Longitude of town B 135°-30° = 105°E.