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Australia/Adelaide time zone

11:25PMACDT

ACDTUTC+10:30+15 h 30 min vs New York (you)

About Australia/Adelaide

Australia/Adelaide is the IANA time zone for South Australia in Australia. It currently keeps Australian Central Standard Time (ACST, UTC+9:30) in winter and Australian Central Daylight Time (ACDT, UTC+10:30) in summer.

Its principal location is Adelaide at 34.92° S, 138.58° E.

Abbreviations in use: ACST, ACDT. Offset page: UTC+9:30.

Rule for future years (POSIX TZ string)

ACST-9:30ACDT,M10.1.0,M4.1.0/3

The standard time is called ACST and is UTC+9:30. POSIX writes the offset with the opposite sign (west of Greenwich is positive), which is why the string says "-9:30". Daylight saving time is called ACDT and is UTC+10:30. It starts on the first Sunday of October at 02:00 and ends on the first Sunday of April at 03:00, 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 Australia/Adelaide since 1970

The record starts with local mean time (UTC+9:14), which ended on January 31, 1895. The first daylight saving time in the record is in 1916.

YearsClocksAbbreviations
1970UTC+9:30 all yearACST
1971UTC+9:30 until October 31, then UTC+10:30ACST, ACDT
1972 onwardUTC+9:30 in winter, UTC+10:30 in summerACDT, ACST

Before 1970

10 offset changes before 1970 in the record:

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

Aliases and zones with the same clock

These older or country-specific IDs are links to Australia/Adelaide in tzdata. Their pages redirect here: Australia/South.

Other zones that keep exactly the same time under the current rules (but have a different history): Australia/Broken_Hill.

Places on Australia/Adelaide

Convert Adelaide time

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

Using Australia/Adelaide 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: 'Australia/Adelaide' })

# Python 3.9+
from zoneinfo import ZoneInfo
from datetime import datetime
datetime.now(ZoneInfo('Australia/Adelaide'))

// Java
java.time.ZonedDateTime.now(java.time.ZoneId.of("Australia/Adelaide"))

// Go
loc, _ := time.LoadLocation("Australia/Adelaide")
time.Now().In(loc)

-- PostgreSQL
SELECT now() AT TIME ZONE 'Australia/Adelaide';

# Shell
TZ='Australia/Adelaide' 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 Australia/Adelaide?
UTC+9:30 in winter and UTC+10:30 in summer (daylight saving time from the first Sunday of October at 2:00 AM to the first Sunday of April at 3:00 AM).
Does Australia/Adelaide observe daylight saving time?
Yes: clocks move one hour forward on the first Sunday of October at 2:00 AM and back on the first Sunday of April at 3:00 AM.
Is Australia/South the same as Australia/Adelaide?
Yes. Australia/South is a link (alias) to Australia/Adelaide in tzdata and gives the same time since 1970. It remains a valid ID.
Which countries use Australia/Adelaide?
Australia, according to zone1970.tab in tzdata.

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