Timetable Reader

Key point

reading a printed timetable

A timetable prints wall times with no offset. The zone it is printed in is what makes each one exact.

scheduleDelivery’s startTimeZone reads a printed departure as a published local time. It resolves a repeated hour to the earlier instant and a skipped hour to the later one. A repeated hour happens twice: an earlier pass and a later pass. An offset written beside the time says which pass is meant.

This tool is about reading a transport timetable. For the general rule behind a repeated or skipped local time in any zone, see the DST Inspector.

1. The timetable

Run time

New York's fall-back night, printed as three timetable rows. 00:30 and 02:30 each happen once; 01:30 happens twice, and the clock alone cannot say which pass a printed 01:30 means.

Drag a handle, or focus it and use the arrow keys, to move that row's printed time. Page Up and Page Down move an hour. The shaded hour is where the clock repeats or skips.

Row 1

Printed departure

Row 2

Printed departure

Row 3

Printed departure

Row 4

Printed departure

2. What each printed time means

• printed time to its instant
• a skipped time, read forward
• run time to arrival
• an hour that repeats
• an hour that is skipped

Printed	Leaves (exact)	Note	Local arrival

For the general rule behind a repeated or skipped hour, see the DST Inspector.

3. What scheduleDelivery returns

 

Worth trying: the spring-forward rows — 01:30, 02:30 and 03:30 printed on New York’s spring-forward night, where 02:30 never shows. Then an offset written into the skipped hour — a skipped time does not exist, so no offset can make it valid.

Reference: scheduleDelivery reads every row here, through its startTimeZone option, the same way resolveLocal resolves a wall time on its own. See the guide’s section on reading a timetable.