On 15 January, when it is 09:00 in New York, it is 15:00 in Paris. That gap is fixed at the abbreviation level: EST sits at UTC−5, CET at UTC+1, a six-hour spread. But right now neither abbreviation is in use. New York runs on Eastern Daylight Time (EDT, UTC−4) and Paris on Central European Summer Time (CEST, UTC+2). The real, place-to-place offset between the two cities shrinks to five hours during summer, and that catches more calendars than it should.

Book the right offset for this week

Add six hours from 1 January to 7 March 2026. New York is on EST and Paris on CET. A 09:00 call in New York lands at 15:00 in Paris. This block lasts 66 days.

Add five hours from 8 March to 28 March 2026. New York has already sprung forward but Paris has not. New York runs UTC−4, Paris stays at UTC+1: only five hours apart. Put a 09:00 meeting in New York at 14:00 Paris time. This is the window that wrecks transatlantic schedules.

Add six hours again from 29 March to 24 October 2026. Both cities are on daylight saving now (EDT and CEST). Paris is six hours ahead. This stretch runs 210 days.

Add five hours from 25 October to 31 October 2026. Paris falls back to CET while New York stays on EDT. The gap drops to five hours.

Add six hours from 1 November to 31 December 2026. New York falls back to EST, and both return to a six-hour spread through the end of the year.

Schedule meetings in the overlap

When the gap is six hours, a 09:00 to 17:00 working day in New York overlaps with Paris for only two hours: 09:00 to 11:00 Eastern. Book transatlantic calls inside that window. When the gap is five hours, the overlap stretches to three hours: 09:00 to 12:00 Eastern. Outside those windows, one side is eating dinner while the other is still at lunch.

Stop writing "EST" in July

EST means Eastern Standard Time (UTC−5), used in winter. EDT means Eastern Daylight Time (UTC−4), used in summer. The same split applies to CET (UTC+1, winter) and CEST (UTC+2, summer). Writing "EST" in July is the most common time zone error. Use "ET" or "Eastern Time" when daylight status does not matter.

Mark the mismatched weeks

New York springs forward on 8 March 2026 at 02:00 local time. From that moment until 28 March, the gap shrinks to five hours. Paris follows on 29 March 2026, pushing the gap back to six. In autumn, Paris falls back on 25 October 2026. New York waits until 1 November 2026. The weeks between those dates are where the five-hour offset lives. Put both pairs in your calendar now.

Tell colleagues in other cities what to expect

On 15 July, relative to Eastern Daylight Time: Los Angeles is three hours behind. Chicago is one hour behind. São Paulo is one hour ahead. London is five hours ahead. Paris is six hours ahead. Johannesburg is six hours ahead. Dubai is eight hours ahead. Mumbai is nine and a half hours ahead. Singapore is twelve hours ahead. Tokyo is thirteen hours ahead. Sydney is fourteen hours ahead.

On 15 January, relative to Eastern Standard Time: Los Angeles is three hours behind. Chicago is one hour behind. São Paulo is two hours ahead. London is five hours ahead. Paris is six hours ahead. Johannesburg is seven hours ahead. Dubai is nine hours ahead. Mumbai is ten and a half hours ahead. Singapore is thirteen hours ahead. Tokyo is fourteen hours ahead. Sydney is sixteen hours ahead.

Know which cities stay on standard time

The IANA zone America/New_York anchors Eastern Time. Other zones that share the same CLDR metazone include America/Toronto, America/Detroit, America/Jamaica, America/Panama, America/Port-au-Prince, America/Cancun, America/Grand_Turk, America/Iqaluit, and several Indiana and Kentucky identifiers. Major cities on the zone: New York (population 8,804,190), Toronto (2,794,356), Brooklyn (2,736,074), Queens (2,316,841), Montréal (1,762,949), Philadelphia (1,573,916), Manhattan (1,487,536), The Bronx (1,385,108), Port-au-Prince (1,234,742), Ottawa (1,017,449), Jacksonville (1,009,833), Kingston (937,700), Columbus (913,175), Charlotte (911,311), and Cancún (888,797). Cancún and Jamaica stay on standard time year-round. Do not factor daylight saving into calls with those two.

Check permanent DST before you rely on it

The US Sunshine Protection Act, which would lock Eastern Time into year-round EDT (UTC−4), passed the Senate in 2022 but stalled in the House. Ontario passed legislation to do the same, but only if New York and Québec act. Québec has consulted but made no decision. Check the current bill status with Congress or the Ontario legislature; the 2022 vote is the last concrete action on record.