Timetables and Itineraries
Reading a timetable
A timetable is a table of times, setting out when services depart and arrive. Each row is one service, like a single bus or train, and the columns give its departure and arrival times. To use one, you find the row you want, then read across to the times. A bus that departs at 8:15 and arrives at 8:50 has both facts on its row. Timetables pack a great deal of information into a small space, and the first skill is simply finding and reading the right row without confusing it with the others.
Working out duration
Duration is how long something lasts, the time that passes between a start and an end. From a departure of 9:20 to an arrival of 10:05 is forty-five minutes; the duration is the gap between the two clock times. Finding it means counting forward from the start to the end, often in two steps: up to the next whole hour, then on to the finishing time. Duration is measured in hours and minutes rather than as a decimal, because time runs in sixties, and it is the quantity most timetable questions ultimately ask for.
Computing a duration
Working out a duration from two times is a counting-on skill. From 14:30 to 16:00, count the half-hour up to 15:00, then the full hour to 16:00, giving one hour and thirty minutes. Crossing an hour boundary is where care is needed: from 11:50 to 12:35 is not eighty-five of anything, but forty-five minutes, found by going ten minutes to 12:00 then thirty-five beyond. Counting on in steps, rather than subtracting the raw numbers, keeps the sixties of the clock straight and gives the right duration every time.
Following an itinerary
An itinerary is an ordered plan of a journey or day, listing each stage with its time: leave home at 8:00, reach the station at 8:25, arrive in the city at 9:10. Where a timetable lists the options, an itinerary is the chosen sequence, one stage flowing into the next. Reading an itinerary means following the stages in order and seeing how the times link up, and the duration of the whole trip is the time from the first stage to the last. Itineraries turn a set of separate times into a single plan that can be followed.
Making connections
Real journeys often involve a connection, where one service must be caught after another arrives. Whether the connection can be made comes down to comparing two times: the arrival of the first service and the departure of the next. Arrive at 9:40 for a bus leaving at 9:55 and there are fifteen minutes to spare; arrive at 14:20 for one that left at 14:15 and it has already gone. This comparison, between when you get in and when the next thing leaves, is one of the most practical uses of reading times from a timetable.
Planning around a time
Often the question runs the other way: given when you must arrive, when should you leave? This means working backwards, subtracting the duration from the deadline. To reach a place by 9:00 after a forty-minute trip, you count back forty minutes to find a latest departure of 8:20. Planning a day from a fixed appointment, a train to catch or a class to reach, uses exactly this reverse calculation. Reading times forward to find a duration and working backward from a deadline are the two directions every itinerary problem is built from.
Where time planning leads
Reading timetables and following itineraries are everyday skills that last a lifetime, from catching a bus to planning a journey across the country. They draw together clock-reading, duration, and the careful arithmetic of a system based on sixties rather than tens. The same thinking extends to scheduling, to time zones, and to any plan where events must be fitted together in time. Being able to read a timetable, work out a duration, and plan backward from a deadline is mathematics that is used far beyond the classroom.