EDT Time Converter

The model, stated exactly

The US Eastern zone is America/New_York in the IANA time-zone database. It observes Eastern Daylight Time (EDT, UTC−4) from the start of daylight saving until daylight saving ends, and Eastern Standard Time (EST, UTC−5) the rest of the year. For the current cycle: EDT runs from March 8, 2026 to November 1, 2026, and EST runs from November 1, 2026 to March 14, 2027, when daylight saving resumes. The converter never assumes the offset from the month: it tries each candidate offset (UTC−4, then UTC−5) for the entered wall time and keeps the one whose New York rendering reproduces the entered date and time exactly, reading the abbreviation from the database itself. Every output zone is then rendered from that UTC instant with Intl.DateTimeFormat. That is why the converter stays correct across the transitions, including the two awkward hours: 1 a.m. on a fall-back day occurs twice (the converter takes the first, daylight occurrence), and 2:30 a.m. on a spring-forward day does not exist at all (the converter reports it as an error instead of silently shifting it).

The worked example, line by line

Setup: Eastern date October 24, 2026, Eastern time 12:00.

Line 1 — the abbreviation. October is in the daylight-saving half, so the zone is EDT (UTC−4).

Line 2 — the UTC instant. 12:00 plus 4 hours = 16:00 UTC on October 24, 2026.

Line 3 — New York. The entered time itself: 12:00 EDT on October 24.

Line 4 — Chicago. CDT (UTC−5): 16:00 UTC = 11:00 CDT on October 24.

Line 5 — Denver. MDT (UTC−6): 16:00 UTC = 10:00 MDT on October 24.

Line 6 — Los Angeles. PDT (UTC−7): 16:00 UTC = 09:00 PDT on October 24.

Line 7 — Anchorage. AKDT (UTC−8): 16:00 UTC = 08:00 AKDT on October 24.

Line 8 — Honolulu. HST (UTC−10, no DST): 16:00 UTC = 06:00 HST on October 24.

Try these

Winter: noon on January 15, 2027. This is EST (UTC−5), so the UTC instant is 17:00 UTC on January 15: 12:00 EST in New York, 11:00 CST in Chicago, 10:00 MST in Denver, 09:00 PST in Los Angeles, 08:00 AKST in Anchorage, and 07:00 HST in Honolulu. Noon Eastern is 11 a.m. Central in both seasons — the UTC anchor is what moves, because both zones shift together.

The boundary days. Noon on March 7, 2026 is still EST (17:00 UTC), and noon on March 8, 2026 is EDT (16:00 UTC), because clocks sprang forward that morning; noon on November 1, 2026 is already EST (17:00 UTC), because daylight saving ended at 2 a.m. that morning. Noon on March 13, 2027 is still EST, and noon on March 14, 2027 is EDT again.

Disambiguation: Australia also uses EDT and EST

The letters EDT and EST are reused in Australia, and they mean different clocks there. Australian Eastern Daylight Time (AEDT) is UTC+11 in the southern summer, and Australian Eastern Standard Time (AEST) is UTC+10 the rest of the year — and, confusingly, Australians often shorten those to EDT and EST in casual writing. So a message saying “noon EDT” from Sydney means 01:00 UTC, while “noon EDT” from New York means 16:00 UTC: a 15-hour gap hidden behind the same three letters. The southern seasons are also reversed — Australian daylight time runs roughly October to April, while US daylight time runs March to November — so the two EDTs are almost never in step. When a message says only “EDT” or “EST” with no place attached, ask which continent before converting: the same letters can mean clocks 15 hours apart.

Output · formula · meaning

Who uses this

• The scheduler writing “noon EDT” in October: enters October 24, 2026 and confirms noon EDT is 16:00 UTC, 11 a.m. in Chicago, and 9 a.m. in Los Angeles — and that the abbreviation is actually correct for that date.
• The manager who wrote “EDT” for a January meeting: enters the January date, sees the converter label it EST, and fixes the invitation before anyone joins an hour late.
• The traveler landing in New York in October: enters October 24, 2026 and learns noon local is EDT, 16:00 UTC — not the 17:00 UTC a winter EST conversion would give.
• The remote worker across three US zones: enters one Eastern time and reads off every US zone at once, including whether Honolulu (which never shifts) has drifted an hour relative to the mainland since the last meeting.

Accuracy & limitations

The conversion is exact for the IANA time-zone database in your browser, which is the same database operating systems and airlines use. Two caveats deserve daylight. First, the converter assumes the time you enter is an Eastern wall-clock time in America/New_York — if a contact quotes you a time labeled only “EDT” or “EST” with no place, check the disambiguation section first, because Australia uses the same letters for UTC+11 / UTC+10 clocks. Second, US daylight-saving rules have changed before (the current March-to-November pattern dates from 2007) and could change again by law; the converter follows whatever rules your browser's database currently carries, which is correct for scheduling today but may differ for far-future dates if the law changes. The fall-back hour (1 a.m. occurring twice) is resolved to its first, daylight occurrence, and the spring-forward gap hour is reported as an error rather than silently shifted. Error policy: empty, malformed, or impossible dates (such as February 30) and nonexistent Eastern times are reported as errors rather than calculated, so no result ever shows a rolled-over date.