Boston runs on America/New_York, and right now that means EDT (UTC−4)

The zone handles two offsets automatically: Eastern Standard Time (UTC−5) in winter, Eastern Daylight Time (UTC−4) in summer. Clocks fall back to EST on Sunday 01 November 2026 at 02:00 local. They spring forward to EDT on Sunday 14 March 2027 at 02:00 local. No manual calculation needed if your device uses IANA data.

Current time in America/New_York

Boston is on Eastern Daylight Time as of this fact sheet (01 October 2026). The next switch arrives the first Sunday in November, when 02:00 rolls back to 01:00 and the city moves to UTC−5. After that, the second Sunday in March restores UTC−4.

What is the IANA time zone database?

Volunteers maintain it. Every operating system relies on it. The database assigns Boston the identifier America/New_York and encodes every DST rule, past and future, so software can compute the correct offset for any date. When a calendar app shows a 9:00 AM Boston call in London, IANA data makes the conversion accurate, even across the transition weeks when the US and UK change clocks on different Sundays.

Why Boston sits in America/New_York

Boston lies near 71.1°W, inside the Eastern zone centered on the 75°W meridian. Railroads imposed Eastern Time on 18 November 1883, the "Day of Two Noons." The Standard Time Act of 1918 wrote it into federal law. Massachusetts has stayed in Eastern Time ever since, though a 2017 state commission studied a shift to Atlantic Time (year-round EDT, effectively) and concluded it would need coordination with other northeastern states. No legislation followed.

EST vs EDT: how America/New_York handles DST

Period Abbreviation UTC Offset
Early November to mid-March EST UTC−5
Mid-March to early November EDT UTC−4

The zone switches on two dates every year. Second Sunday in March: clocks go forward 60 minutes at 02:00 local. First Sunday in November: clocks go back 60 minutes at 02:00 local.

One trap catches people year-round. "ET" is ambiguous. It does not specify whether DST is active. A July meeting listed as "3:00 PM EST" actually means 4:00 PM EDT if the writer was careless. Always confirm EST or EDT.

Cities that share America/New_York

New York, Philadelphia, Washington D.C., Atlanta, Miami. All of Massachusetts. The entire eastern seaboard runs on one clock. No county-level exceptions exist in the state.

Boston time differences, summer and winter

The gap to other cities shifts with the season. On 15 January 2026, under EST, Boston was:

  • 3 hours ahead of Los Angeles
  • 1 hour ahead of Chicago
  • 5 hours behind London
  • 6 hours behind Paris
  • 7 hours behind Johannesburg
  • 2 hours behind São Paulo
  • 9 hours behind Dubai
  • 10.5 hours behind Mumbai
  • 13 hours behind Singapore
  • 14 hours behind Tokyo
  • 16 hours behind Sydney

On 15 July 2026, under EDT, those offsets compress for cities that do not observe DST or that shift on different dates:

  • Los Angeles: 3 hours behind Boston
  • Chicago: 1 hour behind
  • London: 5 hours ahead
  • Paris: 6 hours ahead
  • Johannesburg: 6 hours ahead
  • São Paulo: 1 hour ahead
  • Dubai: 8 hours ahead
  • Mumbai: 9.5 hours ahead
  • Singapore: 12 hours ahead
  • Tokyo: 13 hours ahead
  • Sydney: 14 hours ahead

The 4-hour London gap

Two windows each year break the usual 5-hour difference. The US springs forward roughly two weeks before the UK (mid-March to late March). The US falls back roughly one week after the UK (late October to early November). In both windows, Boston on EDT faces London on GMT: a 4-hour gap. Calendar apps using IANA zones navigate this correctly. Manual math often gets it wrong.

How daylight shifts across the year in America/New_York

Daylight swings hard at this latitude. On the December solstice (21 December 2026), sunrise comes at 07:09 and sunset at 16:14: just 9 hours 5 minutes of daylight. The June solstice (21 June 2026) reverses it: sunrise 05:06, sunset 20:24, giving 15 hours 17 minutes. The March equinox (20 March 2026) delivers sunrise at 06:49 and sunset at 18:55. The September equinox (22 September 2026) brings sunrise at 06:30 and sunset at 18:43.

Solar noon never lands at 12:00. In EST, it runs roughly 11:45 AM. In EDT, roughly 12:45 PM. Photographers chasing golden hour and anyone reading a sundial need that offset.

When do businesses open in America/New_York?

Standard office hours run 9:00 AM to 5:00 PM, Monday to Friday. Financial district firms often start at 8:00 AM and finish at 6:00 PM. Lunch clusters between 12:00 and 1:30 PM. Avoid scheduling calls in that window.

Banks open 9:00 AM to 5:00 PM on weekdays, with some Saturday hours from 9:00 AM to 12:00 PM. Boston City Hall keeps 9:00 AM to 5:00 PM, Monday to Friday. Federal offices run 8:30 AM to 5:00 PM.

Restaurants serve dinner early by European standards: 6:00 to 8:00 PM, with kitchens often closing by 9:30 or 10:00 PM on weeknights. Bars stop serving at 2:00 AM under Massachusetts law.

MBTA subway service runs roughly 5:00 AM to 1:00 AM. Rush hour concentrates 7:30 to 9:30 AM and 4:30 to 6:30 PM, heavier in fall and winter when schools are in session.

Financial markets on America/New_York time

NYSE and NASDAQ operate 9:30 AM to 4:00 PM Eastern Time. Pre-market trading begins at 4:00 AM; after-hours runs until 8:00 PM. The London Stock Exchange (8:00 AM to 4:30 PM GMT/BST) overlaps with New York from 8:00 AM to 11:30 AM Boston time in EST, or 9:00 AM to 12:30 PM in EDT. That window captures peak trading volume.

Which federal holidays close offices in America/New_York?

Federal holidays close government offices and many businesses. The 2026 list:

  • New Year's Day: Thursday 01 January 2026
  • Martin Luther King Jr. Day: Monday 19 January 2026
  • Washington's Birthday: Monday 16 February 2026
  • Memorial Day: Monday 25 May 2026
  • Juneteenth National Independence Day: Friday 19 June 2026
  • Independence Day (observed): Friday 03 July 2026
  • Independence Day: Saturday 04 July 2026
  • Labor Day: Monday 07 September 2026
  • Columbus Day: Monday 12 October 2026
  • Veterans Day: Wednesday 11 November 2026
  • Thanksgiving Day: Thursday 26 November 2026
  • Christmas Day: Friday 25 December 2026
  • New Year's Day: Friday 01 January 2027

Does America/New_York switch to permanent DST?

No. The Sunshine Protection Act passed the Senate in 2022 but stalled in the House. As of 2026, clocks still change twice yearly. No federal law has enacted permanent DST.

"Daylight Savings Time." The correct term is Daylight Saving Time. No "s."

Boston versus New York time. They are identical. Both use America/New_York. Some searches expect a difference; none exists.

UTC versus GMT. GMT is a time zone (UTC+0 in winter). UTC is the standard. Boston is UTC−5 in EST, UTC−4 in EDT. Calling it "GMT−5" year-round is technically correct in winter but misleading in summer.

Date formats. The US writes month/day/year. 3/8/2026 means 08 March 2026, not 03 August. International visitors frequently misread this.

Arizona and Hawaii. Those states opted out of DST under the Uniform Time Act. Massachusetts has not.