Put the calendar date in the message
Tokyo can already be on the next date when New York participants are still in the previous day. Include weekday and full date in any informal message about the meeting. For routine work calls, compare both early-morning and late-evening compromises and discuss who can flex.
New York, US: America/New_York (city ID: new-york).
Tokyo, JP: Asia/Tokyo (city ID: tokyo).
Does the difference change?
The destination-minus-source differences sampled on the 15th of each month in 2027 are +13h, +14h. These are dated examples, not a promise of fixed offsets or a complete historical range. A different reference date may have different rules.
| Source date | New York | Tokyo |
|---|---|---|
| 2027-01-16 | 10:00 Eastern Standard Time | 2027-01-17 · 00:00 +1 day · Japan Standard Time |
| 2027-07-16 | 10:00 Eastern Daylight Time | 2027-07-16 · 23:00 Same day · Japan Standard Time |
Daylight-saving rules depend on the city and date. When a local hour is missing or repeated, the converter rejects it or asks which occurrence you mean. Rules can change politically; reconfirm far-future meetings.