IANA tz database · zone identifier

Africa/Sao_Tome

The IANA tz database identifier for Greenwich Mean Time in São Tomé and Príncipe. Store this string — not the abbreviation, not the offset — and your timestamps stay correct forever.

UTC+00:00Abbreviation GMTNo DST — never observed
Time in Africa/Sao_Tome☾ Night
23:00:33
Wednesday, July 15, 2026
Offset
UTC+00:00
Abbreviation
GMT
DST
No DST

Current offset

UTC+00:00

same year-round

Abbreviation

GMT

used year-round

DST behaviour

Never

has never observed daylight saving

Country

🇸🇹 São Tomé and Príncipe

ISO 3166: ST · view country page →

Using this identifier

The string to put in your code.

Africa/Sao_Tome is the identifier to use in code and config for this region. Every modern language, database, and OS resolves it through the same tz database, so the examples here behave identically everywhere.

Avoid storing GMT or +00:00 — abbreviations are ambiguous and fixed offsets can't follow rule changes.

// format a date in this zone
new Intl.DateTimeFormat('en-US', {
timeZone: 'Africa/Sao_Tome',
dateStyle: 'full', timeStyle: 'long'
}).format(new Date());

Offset & DST behaviour

One offset,
7 years.

Africa/Sao_Tome has kept UTC+00:00 year-round since 1 January 2019 — no daylight saving and no offset changes on record since. It is among the most stable identifiers in the database.

Every offset this zone has kept

+00:26:56UTC+00:00 · UNCHANGED 1 January 2019 NOW

Keeping this offset since

1 January 2019

Next transition

None scheduled

no DST rules exist for this zone

Safe to assume

Local = UTC + 0h, always

…but store the identifier anyway

Technical record

The database entry, in full.

source: IANA tz database

IdentifierAfrica/Sao_Tome
ISO country codeST🇸🇹 São Tomé and Príncipe
Reference coordinates0.33°N, 6.73°Etz database reference point
Standard offsetUTC+00:00abbreviation GMT
Daylight offset—daylight saving has never been observed

Where it applies

All of São Tomé and Príncipe, one clock.

Looking for travel-friendly info? See São Tomé or Greenwich Mean Time.

🇸🇹
São Tomé and Príncipe

204K people, one time zone. The whole country resolves to Africa/Sao_Tome.

Country page →
🇸🇹 São Tomé
23:00
23:00:33 · GMT
pop. 65KGMT

Related identifiers

Nearby in the database.

Same zone group · Greenwich Mean Time

other identifiers keeping GMT

Same offset · UTC+00:00

other zones keeping this offset right now

Frequently asked questions

Answers specific to this identifier — generated from the database record. Can't find what you need? Email [email protected].

What UTC offset is Africa/Sao_Tome?
Africa/Sao_Tome is UTC+00:00, year-round. The offset never changes because the zone does not observe daylight saving time.
Does Africa/Sao_Tome observe daylight saving time?
No. Africa/Sao_Tome has never observed DST — it has kept UTC+00:00 continuously since 1 January 2019.
Which country uses Africa/Sao_Tome?
São Tomé and Príncipe. The identifier covers the whole country.
Is Africa/Sao_Tome the same as GMT?
Africa/Sao_Tome is one of the IANA zones that keeps Greenwich Mean Time (GMT). Use Africa/Sao_Tome in software — GMT is a human-friendly label, not a valid identifier.

Free · Developer API

This zone, as JSON.

Everything on this page — offset, abbreviation, DST rules, coordinates — from one endpoint, always current with the latest tzdb release.

GET /v1/timezones Live

countries, cities, convert, DST transitions coming next.

Get your free API key →
// this identifier, resolved live
GET /v1/timezones?iana=Africa/Sao_Tome
{
"iana": "Africa/Sao_Tome",
"utc_offset": "+00:00",
"abbreviation": "GMT",
"observes_dst": false,
"country": "ST"
}