Jet Lag Recovery Calculator

The human body's internal clock (circadian rhythm) naturally runs slightly longer than 24 hours — closer to 24.2 hours. This makes it easier to delay sleep (westward travel = staying up later) than to advance it (eastward travel = going to bed earlier than your body wants). Flying east from Australia to Europe or North America forces your body to advance its clock by 10+ hours, which is much harder. The same trip in reverse (heading west to the US from Australia) is noticeably easier to recover from.

The most evidence-based strategies are: (1) Get bright outdoor light during daylight hours at your destination — this is the #1 circadian reset trigger; (2) Immediately adopt local mealtimes and sleep times, even if you're not hungry or tired; (3) Avoid naps longer than 20 minutes for the first 2 days; (4) Take 0.5–3mg melatonin at local bedtime for 2–3 nights — research supports this for eastward travel; (5) Stay hydrated and avoid alcohol and heavy meals on your flight. Apps like Timeshifter (developed with jet lag researchers) create personalised adjustment plans.

Yes — melatonin is one of the few supplements with solid scientific evidence for jet lag. A dose of 0.5–3mg taken at the destination's local bedtime (around 10–11pm) for 2–4 nights can shorten recovery time by 1–2 days, especially for eastward travel. Smaller doses (0.5–1mg) are often as effective as larger doses with fewer side effects (grogginess). In Australia, melatonin (Circadin) is available by prescription or over the counter as a complement to good sleep hygiene.