Jet lag plan: Johannesburg to Sydney

The clock moves whether or not you are ready for it. This works out by how much, and what a bedtime walked an hour a night would look like on the way there or once you arrive.

Bedtime and wake time for each night of the plan, and sunset that evening and sunrise the next morning in Sydney, all on the clock you are on now.
Night	Bed	Up	Moved	Sunset there on this clock	Sunrise there on this clock
Night 1	9:00 pm	5:30 am	−1h	9:49 am	9:48 pm
Night 2	8:00 pm	4:30 am	−2h	9:50 am	9:47 pm
Night 3	7:00 pm	3:30 am	−3h	9:51 am	9:45 pm
Night 4	6:00 pm	2:30 am	−4h	9:51 am	9:44 pm
Night 5	5:00 pm	1:30 am	−5h	9:52 am	9:43 pm
Night 6	4:00 pm	12:30 am	−6h	9:53 am	9:41 pm
Night 7	3:00 pm	11:30 pm	−7h	9:53 am	9:40 pm
Night 8	2:00 pm	10:30 pm	−8h	9:54 am	9:38 pm

The gap, and why it is two numbers

In January, Sydney runs 9 hours ahead of Johannesburg. In July it runs 8 hours ahead. Sydney puts its clocks forward for part of the year and Johannesburg does not, so a single figure would be wrong for months at a time. The planner above works from the difference on the date in its field.

What that asks of a bedtime

Taking the shorter way round the dial, the move is 9 hours earlier in January and 8 hours earlier in July. At the planner's usual step of an hour a night, that is 9 nights of shifting in January and 8 in July, either before you fly or after you land.

This is clock arithmetic and nothing else. It does not know how you sleep on aeroplanes, it makes no claim about how quickly anybody adjusts, and an hour a night is a step size rather than a finding. Shorten the step in the planner if a smaller one suits you.

Johannesburg to Sydney through the year

Johannesburg to Sydney is nine hours forward in the southern summer and eight in the winter. South Africa keeps one clock all year, so the gap moves only when New South Wales changes: forward on the first Sunday of October and back on the first Sunday of April.

By the sun, Sydney is about eight hours and thirteen minutes ahead, since it lies 123 degrees further east. The two cities are about 11,040 km apart on the great circle, across the Indian Ocean. Both are in the southern hemisphere, so the seasons do not swap on this route: Sydney's longest days come in December, as Johannesburg's do.

Going east, the move is earlier. A 10:00 pm bedtime in Johannesburg is 7:00 am the next morning in Sydney in January, and 6:00 am in July, and at an hour a night that is nine nights of shifting in the southern summer and eight in the winter. Before you fly in January, the plan brings bedtime forward an hour a night to 1:00 pm on Johannesburg's clock, which is 10:00 pm in Sydney. After you land, the plan starts from 7:00 am local time, the hour a Johannesburg bedtime reads there, and comes back an hour a night to 10:00 pm.

From 3:00 pm in Johannesburg in January, and 4:00 pm in July, Sydney is already on the next calendar day.

Sydney's earliest sunrise, 5:30 am on 3 October in 2026, the last day before its clocks go forward, is 9:30 pm the evening before in Johannesburg. Its latest sunset, 8:10 pm in early January, is 11:10 am in Johannesburg, and Johannesburg's own latest sunset, 7:05 pm in January, is 4:05 am the next day in Sydney. A Johannesburg alarm at 6:30 am is 3:30 pm in Sydney in January and 2:30 pm in July. Perth, on the same continent as Sydney, keeps a clock only six hours ahead of Johannesburg and does not change it. After you land in July, the plan starts from 6:00 am and needs eight nights to come back to 10:00 pm. On the return, the move is eight or nine hours later, over the same number of nights.

Going back

For the return leg, or for anywhere else, the planner takes any pair of cities.

Once you are there

With the clocks settled, the ordinary question comes back: what time to go to bed for the alarm you have set. That is the wake-time pages, which count in cycles rather than in zones.