Menu

Atlantic/Azores time zone

11:54AMUTC−1

UTC−1UTC−1+4 h vs New York (you)

About Atlantic/Azores

Atlantic/Azores is the IANA time zone for Azores in Portugal. It currently keeps UTC−1 in winter and UTC+0 in summer.

Its principal location is Azores at 37.73° N, 25.67° W.

Rule for future years (POSIX TZ string)

<-01>1<+00>,M3.5.0/0,M10.5.0/1

The standard time is called “-01” (a numeric abbreviation) and is UTC−1. POSIX writes the offset with the opposite sign (west of Greenwich is positive), which is why the string says "1". Daylight saving time is called “+00” (a numeric abbreviation) and is UTC+0. It starts on the last Sunday of March at 00:00 and ends on the last Sunday of October at 01:00, local time. Software that has no full tzdata copy, such as many embedded devices, can use this string directly as the TZ environment variable.

Upcoming transitions

Computed from tzdata 2026f; local times are read on the clock just before each change.

History of Atlantic/Azores since 1970

The record starts with local mean time (UTC−1:43), which ended on December 31, 1883. The first daylight saving time in the record is in 1916.

YearsClocksAbbreviations
1970–1981UTC−1 all year—
1982–1992UTC−1 in winter, UTC+0 in summerWET
1993mostly UTC+0; also UTC−1, UTC+1 for part of the yearWET, WEST
1994 onwardUTC−1 in winter, UTC+0 in summer—

Before 1970

101 offset changes before 1970 in the record; the first 12 and the last 12:

tzdata commits to accuracy from 1970 for every zone (zone1970.tab); earlier entries are historical research and may be incomplete.

Convert Azores time

Tip: Alt+↑/↓ steps the time by 15 minutes (Shift: one hour). The link keeps the date, time and direction.

Using Atlantic/Azores in code

Every major platform reads the same IANA ID. Store instants in UTC and convert with the ID at display time; never store a fixed offset for a place that has daylight saving time.

// JavaScript
new Date().toLocaleString('en-US', { timeZone: 'Atlantic/Azores' })

# Python 3.9+
from zoneinfo import ZoneInfo
from datetime import datetime
datetime.now(ZoneInfo('Atlantic/Azores'))

// Java
java.time.ZonedDateTime.now(java.time.ZoneId.of("Atlantic/Azores"))

// Go
loc, _ := time.LoadLocation("Atlantic/Azores")
time.Now().In(loc)

-- PostgreSQL
SELECT now() AT TIME ZONE 'Atlantic/Azores';

# Shell
TZ='Atlantic/Azores' date

Platforms ship their own copy of tzdata and update it on their own schedule. After a rule change, outputs can differ until the platform updates; this page uses tzdata 2026f.

Questions

What is the UTC offset of Atlantic/Azores?
UTC−1 in winter and UTC+0 in summer (daylight saving time from the last Sunday of March at 12:00 AM to the last Sunday of October at 1:00 AM).
Does Atlantic/Azores observe daylight saving time?
Yes: clocks move one hour forward on the last Sunday of March at 12:00 AM and back on the last Sunday of October at 1:00 AM.
Which countries use Atlantic/Azores?
Portugal, according to zone1970.tab in tzdata.

Related