Seoul is 14 hours ahead of New York in winter (EST UTC-5 → KST UTC+9) and 13 hours ahead in summer (EDT UTC-4 → KST UTC+9). A 9:00 AM start in New York is 11:00 PM KST in winter and 10:00 PM KST in summer in Seoul. Best meeting window — Winter (EST): 6:00 PM – 9:00 PM EST (8:00 AM – 11:00 AM KST (+1 day)); Summer (EDT): 6:00 PM – 9:00 PM EDT (7:00 AM – 10:00 AM KST (+1 day)).
With a 14 hours gap in Winter (EST) (EST → KST) and a 13 hours gap in Summer (EDT) (EDT → KST), New York and Seoul have 0 hours of simultaneous 9:00 AM – 5:00 PM business hours in either season. Meetings use morning and early-evening shoulder windows within 7:00 AM – 9:00 PM local time.
Optimal New York–Seoul shoulder bridge for Winter (EST) (14 hours gap) and Summer (EDT) (13 hours gap), ending at or before 9:00 PM local time.
Covers every hour where New York or Seoul is outside 7:00 AM – 9:00 PM local time (20h/day in Winter (EST); 20h/day in Summer (EDT)).
| New York Time | Seoul (Winter (EST → KST)) | Day Shift | Seoul (Summer (EDT → KST)) | Call Status |
|---|---|---|---|---|
| 9:00 AM EST (Morning Start) | 11:00 PM KST | Same day | 10:00 PM KST | Late evening / night |
| 12:00 PM EST (Midday / Noon) | 2:00 AM KST (+1 day) | +1 day | 1:00 AM KST (+1 day) | Overnight / Rest |
| 3:00 PM EST (Afternoon) | 5:00 AM KST (+1 day) | +1 day | 4:00 AM KST (+1 day) | Overnight / Rest |
| 6:00 PM EST (Evening Wrap-up) | 8:00 AM KST (+1 day) | +1 day | 7:00 AM KST (+1 day) | Shoulder Hours |
| New York (EST) | Seoul (Winter (EST → KST)) | Day (Seoul) | Seoul (Summer (EDT → KST)) | Availability (New York ↔ Seoul) |
|---|---|---|---|---|
| 12:00 AM EST in New York | 2:00 PM KST in Seoul | Same day | 1:00 PM KST | New York–Seoul Overnight |
| 1:00 AM EST in New York | 3:00 PM KST in Seoul | Same day | 2:00 PM KST | New York–Seoul Overnight |
| 2:00 AM EST in New York | 4:00 PM KST in Seoul | Same day | 3:00 PM KST | New York–Seoul Overnight |
| 3:00 AM EST in New York | 5:00 PM KST in Seoul | Same day | 4:00 PM KST | New York–Seoul Overnight |
| 4:00 AM EST in New York | 6:00 PM KST in Seoul | Same day | 5:00 PM KST | New York–Seoul Overnight |
| 5:00 AM EST in New York | 7:00 PM KST in Seoul | Same day | 6:00 PM KST | New York–Seoul Overnight |
| 6:00 AM EST in New York | 8:00 PM KST in Seoul | Same day | 7:00 PM KST | New York–Seoul Overnight |
| 7:00 AM EST in New York | 9:00 PM KST in Seoul | Same day | 8:00 PM KST | New York–Seoul Late evening / night |
| 8:00 AM EST in New York | 10:00 PM KST in Seoul | Same day | 9:00 PM KST | New York–Seoul Late evening / night |
| 9:00 AM EST in New York | 11:00 PM KST in Seoul | Same day | 10:00 PM KST | New York–Seoul Late evening / night |
| 10:00 AM EST in New York | 12:00 AM KST in Seoul | +1 day | 11:00 PM KST | New York–Seoul Overnight |
| 11:00 AM EST in New York | 1:00 AM KST in Seoul | +1 day | 12:00 AM KST (+1 day) | New York–Seoul Overnight |
| 12:00 PM EST in New York | 2:00 AM KST in Seoul | +1 day | 1:00 AM KST (+1 day) | New York–Seoul Overnight |
| 1:00 PM EST in New York | 3:00 AM KST in Seoul | +1 day | 2:00 AM KST (+1 day) | New York–Seoul Overnight |
| 2:00 PM EST in New York | 4:00 AM KST in Seoul | +1 day | 3:00 AM KST (+1 day) | New York–Seoul Overnight |
| 3:00 PM EST in New York | 5:00 AM KST in Seoul | +1 day | 4:00 AM KST (+1 day) | New York–Seoul Overnight |
| 4:00 PM EST in New York | 6:00 AM KST in Seoul | +1 day | 5:00 AM KST (+1 day) | New York–Seoul Overnight |
| 5:00 PM EST in New York | 7:00 AM KST in Seoul | +1 day | 6:00 AM KST (+1 day) | New York–Seoul Shoulder |
| 6:00 PM EST in New York | 8:00 AM KST in Seoul | +1 day | 7:00 AM KST (+1 day) | New York–Seoul Shoulder |
| 7:00 PM EST in New York | 9:00 AM KST in Seoul | +1 day | 8:00 AM KST (+1 day) | New York–Seoul Shoulder |
| 8:00 PM EST in New York | 10:00 AM KST in Seoul | +1 day | 9:00 AM KST (+1 day) | New York–Seoul Shoulder |
| 9:00 PM EST in New York | 11:00 AM KST in Seoul | +1 day | 10:00 AM KST (+1 day) | New York–Seoul Late evening / night |
| 10:00 PM EST in New York | 12:00 PM KST in Seoul | +1 day | 11:00 AM KST (+1 day) | New York–Seoul Late evening / night |
| 11:00 PM EST in New York | 1:00 PM KST in Seoul | +1 day | 12:00 PM KST (+1 day) | New York–Seoul Late evening / night |
Between New York (United States, America/New_York) and Seoul (South Korea, Asia/Seoul), the seasonal offset shifts by 1 hour. In winter standard time (EST vs. KST), Seoul (UTC+9) is 14 hours ahead of New York (UTC-5). In summer (EDT vs. KST), Seoul (UTC+9) is 13 hours ahead of New York (UTC-4).
No Daylight Saving Time observed. Remains on KST (UTC+9) year-round.
| Date Window | Duration | Active Zones | Time Difference | Regime |
|---|---|---|---|---|
| Since Nov 1, 2026 | 133 days | EST (UTC-5) → KST (UTC+9) | 14 hours | Standard Alignment (Active Now) |
| Mar 14, 2027 – Nov 3, 2027 | 234 days | EDT (UTC-4) → KST (UTC+9) | 13 hours | Standard Alignment |
Because Seoul is 14 hours ahead in winter and 13 hours ahead in summer, Seoul enters the next calendar day (+1 day) at 10:00 AM EST in winter and 11:00 AM EDT in summer in New York. Before that cutoff, both locations share the same weekday; from 10:00 AM EST (11:00 AM EDT in summer) until midnight in New York, Mon–Fri in New York maps to Tue–Sat in Seoul.
Weekend & Workday Alignment: Friday afternoon/evening in New York (any slot at or after 10:00 AM EST / 11:00 AM EDT in summer) lands on Saturday morning/afternoon in Seoul—which is Seoul's weekend (Sat–Sun). Conversely, Monday morning in Seoul (before 2:00 PM KST) is still Sunday in New York (New York's Sat–Sun weekend). For late-day New York / morning Seoul syncs, book Monday–Thursday in New York (Tuesday–Friday in Seoul).
Geographically, New York (United States, 40.71°N, 74.01°W, IATA: JFK/EWR/LGA) and Seoul (South Korea, 37.57°N, 126.98°E, IATA: ICN) are separated by a great-circle distance of 11,053 km (6,868 miles, approximately 13.5h non-stop flight). By longitude, true solar time in Seoul is 13 hours and 24 minutes ahead of New York (a 36-minute divergence from the 14 hours standard civil clock offset): New York (40.71°N, 74.01°W) sits 0.99° east of the 75.0°W EST reference meridian, so mean solar noon occurs at 11:56 AM EST in winter and 12:56 PM EDT in summer, while Seoul (37.57°N, 126.98°E) sits 8.02° west of the 135.0°E KST reference meridian, so mean solar noon occurs at 12:32 PM KST year-round.
In winter (standard time), Seoul (KST, UTC+9) is 14 hours ahead of New York (EST, UTC-5). In summer (daylight saving time), Seoul (KST, UTC+9) is 13 hours ahead of New York (EDT, UTC-4).
No — 4:00 PM in New York is 6:00 AM KST (+1 day) in winter and 5:00 AM KST (+1 day) in summer in Seoul, which is outside the 7:00 AM – 9:00 PM calling window. Book calls during 6:00 PM – 9:00 PM EST in winter or 6:00 PM – 9:00 PM EDT in summer.
In winter (EST), the best window is 6:00 PM – 9:00 PM EST in New York (8:00 AM – 11:00 AM KST (+1 day) in Seoul). In summer (EDT), use 6:00 PM – 9:00 PM EDT in New York (7:00 AM – 10:00 AM KST (+1 day) in Seoul). Avoid hours outside 7:00 AM – 9:00 PM local time (9:00 PM – 5:00 PM EST (+1 day) in winter; 9:00 PM – 7:00 AM EDT (+1 day) & 8:00 AM – 6:00 PM EDT in summer).
New York: Sun, Mar 14, 2027 (EST → EDT, new gap: 13 hours (EDT UTC-4 vs KST UTC+9)). Seoul: No DST (KST year-round).
In winter (EST), 9:00 AM New York is 11:00 PM KST and 12:00 PM is 2:00 AM KST (+1 day) in Seoul. In summer (EDT), 9:00 AM is 10:00 PM KST and 12:00 PM is 1:00 AM KST (+1 day).