Busan is 12 hours ahead of Brasília. You're traveling east — the harder direction. Your body must advance its clock.
About 17,838 km due north · approximately 21.5-hour non-stop flight · an ultra-long-haul flight.
3 days before departure
Bedtime
Move bedtime 3h earlier than normal
Wake
Wake 3h earlier
Light
Bright light immediately on wake (sunlight or 10,000-lux box, 30–60 min)
Avoid light
Dim lights and avoid screens 2h before the new bedtime
Melatonin
Optional: 0.5 mg melatonin 5h before target bedtime (consult doctor; avoid if on SSRIs/blood thinners)
Anchor each step with light exposure — the light is doing the work.
2 days before departure
Bedtime
Move bedtime 2h earlier than normal
Wake
Wake 2h earlier
Light
Bright light immediately on wake (sunlight or 10,000-lux box, 30–60 min)
Avoid light
Dim lights and avoid screens 2h before the new bedtime
Melatonin
Optional: 0.5 mg melatonin 5h before target bedtime (consult doctor; avoid if on SSRIs/blood thinners)
Anchor each step with light exposure — the light is doing the work.
1 day before departure
Bedtime
Move bedtime 1h earlier than normal
Wake
Wake 1h earlier
Light
Bright light immediately on wake (sunlight or 10,000-lux box, 30–60 min)
Avoid light
Dim lights and avoid screens 2h before the new bedtime
Melatonin
Optional: 0.5 mg melatonin 5h before target bedtime (consult doctor; avoid if on SSRIs/blood thinners)
Anchor each step with light exposure — the light is doing the work.
On the flight
Set your watch to the destination time as soon as you board.
Sleep when it’s night at the destination, even if you’re not tired.
Avoid alcohol and excess caffeine — both disrupt sleep architecture and worsen jet lag.
Hydrate steadily; cabin humidity is ~10–20%.
Day of arrival
Bedtime
Aim for local bedtime even if you’re wide awake
Light
Morning bright light at the destination (sunlight is ideal) for at least 30 min
Avoid light
Wear sunglasses in the late afternoon and avoid bright light after dusk
Melatonin
0.5 mg melatonin 30 min before destination bedtime (Cochrane: effective for ≥5h eastward)
Resist the urge to nap longer than 20–30 minutes — it will compound the lag.
Day 2 at destination
Light
Continue morning bright light for the first 3–5 days
Avoid light
Avoid bright evening light until you’re fully adjusted
Melatonin
0.5 mg melatonin before bedtime (continue 2–4 nights)
Eat meals on the local schedule — meal timing reinforces the new circadian phase.
Day 3 at destination
Light
Continue morning bright light for the first 3–5 days
Avoid light
Avoid bright evening light until you’re fully adjusted
Melatonin
0.5 mg melatonin before bedtime (continue 2–4 nights)
Eat meals on the local schedule — meal timing reinforces the new circadian phase.
Day 4 at destination
Light
Continue morning bright light for the first 3–5 days
Avoid light
Avoid bright evening light until you’re fully adjusted
Eat meals on the local schedule — meal timing reinforces the new circadian phase.
Day 5 at destination
Light
Continue morning bright light for the first 3–5 days
Avoid light
Avoid bright evening light until you’re fully adjusted
Eat meals on the local schedule — meal timing reinforces the new circadian phase.
Day 6 at destination
Light
Continue morning bright light for the first 3–5 days
Avoid light
Avoid bright evening light until you’re fully adjusted
Eat meals on the local schedule — meal timing reinforces the new circadian phase.
Day 7 at destination
Light
Continue morning bright light for the first 3–5 days
Avoid light
Avoid bright evening light until you’re fully adjusted
Eat meals on the local schedule — meal timing reinforces the new circadian phase.
Day 8 at destination
Light
Continue morning bright light for the first 3–5 days
Avoid light
Avoid bright evening light until you’re fully adjusted
Eat meals on the local schedule — meal timing reinforces the new circadian phase.
About the Brasília → Busan route
The route from Brasília, Brazil to Busan, South Korea covers roughly 17,838 kilometres in a due north direction. At standard jet cruise speed plus a one-hour allowance for taxi, climb, and descent, a non-stop flight takes about 21.5 hours. This route crosses the equator. The destination's season is reversed relative to the origin, which can amplify the perceived disorientation of jet lag — your body lands not just in a different clock but in a different daylight regime.
Brasília is in the tropics, so day length varies only slightly across the year. Light cues for the circadian system stay strong year-round. Busan is in the temperate zone. Day length varies by four to six hours between summer and winter, so the season of your trip materially affects available morning and evening light.
Business-hours overlap
With a 12-hour offset, the standard 09:00–18:00 working days in Brasília and Busan do not overlap. Live collaboration on this route requires at least one side to take an early or late call. The least costly compromise is usually an early-morning call in Brasília and a late-evening call in Busan.
Daylight saving on this route
Neither city observes daylight saving time, so the hour offset on this route is fixed year-round. This makes recurring schedules and calendar invites with collaborators on the other end safer than for DST-observing pairs.
Your chronotype on this route
If you are a lark (morning type): Larks recover faster on eastward routes because their circadian phase is already advanced relative to the population. Plan to be in bed one hour earlier than your usual time for two or three nights before departure, and seek bright light immediately on waking at the destination. Most larks adjust to a 12-hour eastward shift in 8 days.
If you are a night owl (evening type): Owls struggle with eastward travel. Your biology resists advancing; a 12-hour eastward shift will typically take 12 days to clear, with the worst days being day two and three. Pre-trip phase advance (going to bed 30–60 minutes earlier per day for 4 days) and morning bright light at the destination are the highest-evidence interventions.
The great-circle distance from Brasília to Busan is about 17,838 kilometres. A typical non-stop flight takes around 21.5 hours at standard cruise speed; routes with connections add two to four hours.
What is the time difference between Brasília and Busan?
Busan is currently 12 hours ahead of Brasília. Neither city observes daylight saving time, so the hour offset on this route is fixed year-round. This makes recurring schedules and calendar invites with collaborators on the other end safer than for DST-observing pairs.
Is jet lag worse flying east or west on this route?
Eastward travel — which this route is — is the harder direction for most travellers. Your body must advance its clock, and the population shifts about one hour per day under good conditions. Expect 12 days to fully clear a 12-hour eastward shift.
Should I take melatonin for the Brasília → Busan trip?
For a 12-hour shift, 0.3 to 0.5 mg of melatonin taken three to five hours before target bedtime at the destination is the dose supported by the Cochrane review. Higher doses (3–5 mg) do not advance phase better and increase morning grogginess. Start one day before departure.
Do I need a pre-trip schedule shift for Brasília → Busan?
Yes — for shifts of four hours or more, shifting bedtime and wake time by one hour per day, starting three days before departure, materially reduces post-arrival jet lag.
What chronotype handles this route best?
Larks (morning types) recover faster on eastward routes because their circadian phase is already advanced relative to the population. Owls (evening types) typically need an extra day or two.