Seoul is 16 to 17 hours ahead of Seattle, depending on the time of year. If you are both awake 7 am to 11 pm, a January weekday gives you 9 hours awake at the same time, though none of them is outside a 9-to-5 for both of you (in July: 8 hours shared, 0 hours free). Here are the good ones.
Seoul is 17 hours ahead of Seattle that week. On a weekday you are both awake for 9 hours, but none of them is outside work for both of you, so a lunch break or a commute has to do the work.
Worked out for the week of 11 January 2027 (11 Jan – 17 Jan), in Seattle time, with each zone’s own daylight-saving rules for those dates. Seoul awake 7 am – 11 pm, working 9 am – 5 pm weekdays; Seattle awake 7 am – 11 pm, working 9 am – 5 pm weekdays.
A weekday, in Seattle timeboth awake
Seattleawake 7 am – 11 pm
Seoulawake 2 pm – 6 am Seattle time
7a10a1p4p7p10p1a4a7a
Best on a weekday
7 – 9 pm Seattle
noon – 2 pm Seoul · Seattle evening, Seoul lunchtime (their next day) · during Seoul’s lunch break
Another weekday option
2 – 4 pm Seattle
7 – 9 am Seoul · Seattle afternoon, Seoul morning (their next day) · during Seattle’s work hours
The long weekend call
Sat 6 – 9 pm Seattle
Sun 11 am – 2 pm Seoul · Seattle early evening, Seoul lunchtime
The week · Seattle time, 11 Jan – 17 Jan
7a
8a
9a
10a
11a
12p
1p
2p
3p
4p
5p
6p
7p
8p
9p
10p
Mon
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Tue
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Wed
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Thu
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Fri
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Sat
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Sun
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Columns are Seattle hours; the small figure in each cell is the time in Seoul. both freeboth awake, one at workSeoul asleep
The Seoul–Seattle gap through 2027
Dates
Difference
1 January – 13 March
Seoul is 17 hours ahead of Seattle
14 March – 6 November
Seoul is 16 hours ahead of Seattle
7 November – 31 December
Seoul is 17 hours ahead of Seattle
The week grid and call windows were worked out for 11 Jan to 17 Jan 2027 with the IANA time-zone rules for Asia/Seoul (Seoul) and America/Los_Angeles (Seattle). That week Seattle is on standard time and Seoul keeps the same time all year. The table uses the same rules for every day of 2027. The finder above recalculates for the current week in your browser.
When it is … in Seattle
In Seattle
Seoul, January
Seoul, July
7 am
midnight (next day)
11 pm
9 am
2 am (next day)
1 am (next day)
11 am
4 am (next day)
3 am (next day)
1 pm
6 am (next day)
5 am (next day)
3 pm
8 am (next day)
7 am (next day)
5 pm
10 am (next day)
9 am (next day)
7 pm
noon (next day)
11 am (next day)
9 pm
2 pm (next day)
1 pm (next day)
Wednesday times. Send times as “your 8 pm” or “my 8 pm” so nobody has to guess whose clock you mean.
Stop doing the math every day
The Long Goodbye keeps your person’s local time and time of day on your home-screen widget and lock screen, so you can see whether it is morning coffee or midnight in Seoul before you call. A “thinking of you” tap lights up their widget, and a countdown keeps the next visit in view.
What is the time difference between Seoul and Seattle?
Seoul is 16 to 17 hours ahead of Seattle, depending on the time of year. In 2027 it is 17 hours from 1 January to 13 March and from 7 November to 31 December; 16 hours from 14 March to 6 November.
What is the best time to call Seoul from Seattle?
In January, the easiest two hours on a weekday are 7 – 9 pm Seattle, which is noon – 2 pm Seoul: Seattle evening, Seoul lunchtime, the next day there, during Seoul’s lunch break. At the weekend, Sat 6 – 9 pm Seattle (Sun 11 am – 2 pm Seoul) gives you a longer call. Change the awake and work hours in the finder on this page to fit your own days.
How many waking hours do Seoul and Seattle share?
If both of you are awake from 7 am to 11 pm, you share 9 hours on a January weekday, but none of them falls outside 9-to-5 working hours in both places; in July it is 8 hours shared and 0 hours free.
Does daylight saving time change the call times?
Yes. In 2027 Seattle changes its clocks on 14 March and 7 November and Seoul does not change its clocks, so a call you keep at the same time in Seattle moves by an hour in Seoul on those dates. Check the table on this page and agree the new time out loud after each change.