Tokyo is 9 hours ahead of Dublin in winter (GMT UTC+0 → JST UTC+9) and 8 hours ahead in summer (IST UTC+1 → JST UTC+9). A 9:00 AM start in Dublin is 6:00 PM JST in winter and 5:00 PM JST in summer in Tokyo. Best meeting window — Winter (GMT): 9:00 AM – 12:00 PM GMT (6:00 PM – 9:00 PM JST); Summer (IST): 8:30 AM – 11:30 AM IST (4:30 PM – 7:30 PM JST).
With a 9 hours gap in Winter (GMT) (GMT → JST) and a 8 hours gap in Summer (IST) (IST → JST), Dublin and Tokyo 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 Dublin–Tokyo shoulder bridge for Winter (GMT) (9 hours gap) and Summer (IST) (8 hours gap), ending at or before 9:00 PM local time.
Covers every hour where Dublin or Tokyo is outside 7:00 AM – 9:00 PM local time (19h/day in Winter (GMT); 18h/day in Summer (IST)).
| Dublin Time | Tokyo (Winter (GMT → JST)) | Day Shift | Tokyo (Summer (IST → JST)) | Call Status |
|---|---|---|---|---|
| 9:00 AM GMT (Morning Start) | 6:00 PM JST | Same day | 5:00 PM JST | Shoulder Hours |
| 12:00 PM GMT (Midday / Noon) | 9:00 PM JST | Same day | 8:00 PM JST | Late evening / night |
| 3:00 PM GMT (Afternoon) | 12:00 AM JST (+1 day) | +1 day | 11:00 PM JST | Overnight / Rest |
| 6:00 PM GMT (Evening Wrap-up) | 3:00 AM JST (+1 day) | +1 day | 2:00 AM JST (+1 day) | Overnight / Rest |
| Dublin (GMT) | Tokyo (Winter (GMT → JST)) | Day (Tokyo) | Tokyo (Summer (IST → JST)) | Availability (Dublin ↔ Tokyo) |
|---|---|---|---|---|
| 12:00 AM GMT in Dublin | 9:00 AM JST in Tokyo | Same day | 8:00 AM JST | Dublin–Tokyo Overnight |
| 1:00 AM GMT in Dublin | 10:00 AM JST in Tokyo | Same day | 9:00 AM JST | Dublin–Tokyo Overnight |
| 2:00 AM GMT in Dublin | 11:00 AM JST in Tokyo | Same day | 10:00 AM JST | Dublin–Tokyo Overnight |
| 3:00 AM GMT in Dublin | 12:00 PM JST in Tokyo | Same day | 11:00 AM JST | Dublin–Tokyo Overnight |
| 4:00 AM GMT in Dublin | 1:00 PM JST in Tokyo | Same day | 12:00 PM JST | Dublin–Tokyo Overnight |
| 5:00 AM GMT in Dublin | 2:00 PM JST in Tokyo | Same day | 1:00 PM JST | Dublin–Tokyo Overnight |
| 6:00 AM GMT in Dublin | 3:00 PM JST in Tokyo | Same day | 2:00 PM JST | Dublin–Tokyo Overnight |
| 7:00 AM GMT in Dublin | 4:00 PM JST in Tokyo | Same day | 3:00 PM JST | Dublin–Tokyo Shoulder |
| 8:00 AM GMT in Dublin | 5:00 PM JST in Tokyo | Same day | 4:00 PM JST | Dublin–Tokyo Shoulder |
| 9:00 AM GMT in Dublin | 6:00 PM JST in Tokyo | Same day | 5:00 PM JST | Dublin–Tokyo Shoulder |
| 10:00 AM GMT in Dublin | 7:00 PM JST in Tokyo | Same day | 6:00 PM JST | Dublin–Tokyo Shoulder |
| 11:00 AM GMT in Dublin | 8:00 PM JST in Tokyo | Same day | 7:00 PM JST | Dublin–Tokyo Shoulder |
| 12:00 PM GMT in Dublin | 9:00 PM JST in Tokyo | Same day | 8:00 PM JST | Dublin–Tokyo Late evening / night |
| 1:00 PM GMT in Dublin | 10:00 PM JST in Tokyo | Same day | 9:00 PM JST | Dublin–Tokyo Late evening / night |
| 2:00 PM GMT in Dublin | 11:00 PM JST in Tokyo | Same day | 10:00 PM JST | Dublin–Tokyo Late evening / night |
| 3:00 PM GMT in Dublin | 12:00 AM JST in Tokyo | +1 day | 11:00 PM JST | Dublin–Tokyo Overnight |
| 4:00 PM GMT in Dublin | 1:00 AM JST in Tokyo | +1 day | 12:00 AM JST (+1 day) | Dublin–Tokyo Overnight |
| 5:00 PM GMT in Dublin | 2:00 AM JST in Tokyo | +1 day | 1:00 AM JST (+1 day) | Dublin–Tokyo Overnight |
| 6:00 PM GMT in Dublin | 3:00 AM JST in Tokyo | +1 day | 2:00 AM JST (+1 day) | Dublin–Tokyo Overnight |
| 7:00 PM GMT in Dublin | 4:00 AM JST in Tokyo | +1 day | 3:00 AM JST (+1 day) | Dublin–Tokyo Overnight |
| 8:00 PM GMT in Dublin | 5:00 AM JST in Tokyo | +1 day | 4:00 AM JST (+1 day) | Dublin–Tokyo Overnight |
| 9:00 PM GMT in Dublin | 6:00 AM JST in Tokyo | +1 day | 5:00 AM JST (+1 day) | Dublin–Tokyo Overnight |
| 10:00 PM GMT in Dublin | 7:00 AM JST in Tokyo | +1 day | 6:00 AM JST (+1 day) | Dublin–Tokyo Late evening / night |
| 11:00 PM GMT in Dublin | 8:00 AM JST in Tokyo | +1 day | 7:00 AM JST (+1 day) | Dublin–Tokyo Late evening / night |
Between Dublin (Ireland, Europe/Dublin) and Tokyo (Japan, Asia/Tokyo), the seasonal offset shifts by 1 hour. In winter standard time (GMT vs. JST), Tokyo (UTC+9) is 9 hours ahead of Dublin (UTC+0). In summer (IST vs. JST), Tokyo (UTC+9) is 8 hours ahead of Dublin (UTC+1).
No Daylight Saving Time observed. Remains on JST (UTC+9) year-round.
| Date Window | Duration | Active Zones | Time Difference | Regime |
|---|---|---|---|---|
| Since Oct 25, 2026 | 154 days | GMT (UTC+0) → JST (UTC+9) | 9 hours | Standard Alignment (Active Now) |
| Mar 28, 2027 – Oct 31, 2027 | 217 days | IST (UTC+1) → JST (UTC+9) | 8 hours | Standard Alignment |
| Oct 31, 2027 – Nov 3, 2027 | 3 days | GMT (UTC+0) → JST (UTC+9) | 9 hours | Standard Alignment |
Because Tokyo is 9 hours ahead in winter and 8 hours ahead in summer, Tokyo enters the next calendar day (+1 day) at 3:00 PM GMT in winter and 4:00 PM IST in summer in Dublin. Before that cutoff, both locations share the same weekday; from 3:00 PM GMT (4:00 PM IST in summer) until midnight in Dublin, Mon–Fri in Dublin maps to Tue–Sat in Tokyo.
Weekend & Workday Alignment: Friday afternoon/evening in Dublin (any slot at or after 3:00 PM GMT / 4:00 PM IST in summer) lands on Saturday morning/afternoon in Tokyo—which is Tokyo's weekend (Sat–Sun). Conversely, Monday morning in Tokyo (before 9:00 AM JST) is still Sunday in Dublin (Dublin's Sat–Sun weekend). For late-day Dublin / morning Tokyo syncs, book Monday–Thursday in Dublin (Tuesday–Friday in Tokyo).
Geographically, Dublin (Ireland, 53.35°N, 6.26°W, IATA: DUB) and Tokyo (Japan, 35.68°N, 139.65°E, IATA: HND/NRT) are separated by a great-circle distance of 9,585 km (5,956 miles, approximately 12h non-stop flight). By longitude, true solar time in Tokyo is 9 hours and 44 minutes ahead of Dublin (a 44-minute divergence from the 9 hours standard civil clock offset): Dublin (53.35°N, 6.26°W) sits 6.26° west of the 0.0°E GMT reference meridian, so mean solar noon occurs at 12:25 PM GMT in winter and 1:25 PM IST in summer, while Tokyo (35.68°N, 139.65°E) sits 4.65° east of the 135.0°E JST reference meridian, so mean solar noon occurs at 11:41 AM JST year-round.
For Dublin → Tokyo: India Standard Time (IST, UTC+5:30) is a single national half-hour offset observed year-round across all of India (IANA zone Asia/Kolkata) with no Daylight Saving Time. Note: Neighboring Sri Lanka shares the same UTC+5:30 offset year-round under its own IANA timezone (Asia/Colombo, Sri Lanka Standard Time / SLST).
| Abbreviation Meaning | UTC Offset | IANA Zone | Major Cities & Regions |
|---|---|---|---|
| India Standard Time Primary Here | UTC+5:30 (year-round, no DST) | Asia/Kolkata | Not used for Dublin → Tokyo: Mumbai, New Delhi, Bengaluru, Hyderabad, Chennai, Pune (India) |
| Irish Standard Time Primary Here | UTC+1 (summer only; GMT UTC+0 in winter) | Europe/Dublin | Active on Dublin → Tokyo: Dublin, Cork, Galway (Ireland) |
| Israel Standard Time | UTC+2 (IDT UTC+3 in summer) | Asia/Jerusalem | Not used for Dublin → Tokyo: Tel Aviv, Jerusalem (Israel) |
In winter (standard time), Tokyo (JST, UTC+9) is 9 hours ahead of Dublin (GMT, UTC+0). In summer (daylight saving time), Tokyo (JST, UTC+9) is 8 hours ahead of Dublin (IST, UTC+1).
No — 4:00 PM in Dublin is 1:00 AM JST (+1 day) in winter and 12:00 AM JST (+1 day) in summer in Tokyo, which is outside the 7:00 AM – 9:00 PM calling window. Book calls during 9:00 AM – 12:00 PM GMT in winter or 8:30 AM – 11:30 AM IST in summer.
In winter (GMT), the best window is 9:00 AM – 12:00 PM GMT in Dublin (6:00 PM – 9:00 PM JST in Tokyo). In summer (IST), use 8:30 AM – 11:30 AM IST in Dublin (4:30 PM – 7:30 PM JST in Tokyo). Avoid hours outside 7:00 AM – 9:00 PM local time (12:00 PM – 7:00 AM GMT (+1 day) in winter; 1:00 PM – 7:00 AM IST (+1 day) in summer).
Dublin: Sun, Mar 28, 2027 (GMT → IST, new gap: 8 hours (IST UTC+1 vs JST UTC+9)). Tokyo: No DST (JST year-round).
In winter (GMT), 9:00 AM Dublin is 6:00 PM JST and 12:00 PM is 9:00 PM JST in Tokyo. In summer (IST), 9:00 AM is 5:00 PM JST and 12:00 PM is 8:00 PM JST.