City comparison · time difference and converter
San Francisco is 16 hours behind Daejeon right now. Daejeon sits in South Korea on Seoul; San Francisco sits in United States on Los Angeles. They are roughly 9,092 km apart (5,650 mi), a flight of about 11h 42m. Daejeon's metro holds around 1.4 million people; San Francisco's around 4.7 million.
Slot 1
01:00 / 09:00
Daejeon / San Francisco
Partial overlapSlot 2
02:00 / 10:00
Daejeon / San Francisco
Partial overlapSlot 3
03:00 / 11:00
Daejeon / San Francisco
Partial overlapEach row is one hour in Daejeon. Green rows are inside business hours in both cities; amber means only one side is at their desk; grey rows fall outside business hours in both.
Local Election Day
Daejeon, South Korea · 지방 선거일
Wed, Jun 3
Memorial Day
Daejeon, South Korea · 현충일
Sat, Jun 6
Juneteenth
San Francisco, United States
Fri, Jun 19
Great-circle distance
9,092 km
(5,650 mi)
Approximate flight
11h 42m
850 km/h cruise + 1h taxi/climb/descent
Jet lag
16h
Roughly 1 day to adjust per timezone crossed
The heatmap gives you the shape of the day. If you need to convert one specific hour — say a customer call or a release window — open the converter with both cities already loaded.
Open in converter →The difference between Daejeon and San Francisco is not really a number, it's a daily rhythm. San Francisco is 16 hours behind Daejeon on the clock today, but the lived version is that Daejeon is ahead in the calendar, so by the time San Francisco comes online, half of Daejeon's day is already gone. That gap, more than the raw offset, is what teams have to design around.
In Daejeon, the working day picks up earliest in the financial districts — Daejeon's downtown core wakes early and breaks for lunch at the usual hour. The mood in San Francisco is its own story: SoMa and FiDi quiet around 18:00, with Mission bars taking the after-work crowd. If you are scheduling between the two, the heatmap above marks the rows where both patterns line up.
Daylight saving is the other thing to keep an eye on. South Korea either observes DST or holds a fixed offset year-round; United States shifts on the second Sunday of March and the first Sunday of November. When the two changes are weeks apart, the offset between Daejeon and San Francisco is one hour off the usual for that stretch — a cliff that catches recurring calendar invites unless your calendar app rebases them automatically. Pin the meeting to a city, not an offset, and the tool handles the rest.
For travellers, the 11h 42m flight is the short version of the story. The longer one is jet lag: roughly one day of adjustment per timezone crossed, which means a trip across the 16-hour gap costs about 16 groggy days on each side. Pilots and cabin crew swear by morning sunlight and an early walk; whatever your routine, the wall-clock numbers above are the source of truth for your first morning in the new city.