Public transport operates on the basis of timetable years. This usually lasts one year, but it begins on the second weekend in December. The list about the upcoming timetable change can be exported from the dataset “Timetableoverview“.
The reason for having a separate public transport calendar is not only down to the difference between the calendar year and timetable year, but also to planning and customer information. Up until a couple of years ago, basically, only three timetables were produced: weekdays (Monday to Friday), Saturday and Sunday. These three timetables were then assigned to the relevant calendar days. An additional calendar was also introduced at that time by the IT department. As IT continued to develop, the variations of timetables evolved, to the point that we have gone from the original three timetables across one timetable year to planning nowadays using up to 365 different timetable a year.
This variability is reflected specifically in the timetable data calendar on the Open data platform.
A timetable year is not always the same length either. For processing purposes, 400 days are adopted. There is, for instance:
- Operates every day: 1-7
- Operates only on Mondays: 1
Both these “patterns” belong to the perpetual patterns as they will always be the same. As the timetable change always takes place on the same weekday, the timetable year also starts on the same weekday.
- Operating day: The operating day is a single day (date) on which a train operates according to plan. The quantity of operating days within a timetable period corresponds to the train’s operating period.
The days on which a form of transport is operating is saved as a bitmap. Each bitmap is given a code. Perpetual patterns have the same code every year. Otherwise, new patterns, which are defined for their timetables according to the transport companies’ needs, are given new codes. All these patterns are saved in HRDF in the “BITFELD” file:
Perpetual pattern “000017” is easy to recognise. In HRDF the first two bits are always set and another two set bits must be added according to the timetable year. To be able to process timetables, an understanding of the relevant bitmaps is an absolute requirement.
More detailed information