Factory time zone

About Factory

Factory is a placeholder zone with the numeric abbreviation “-00”, meaning that the local time is unknown. It exists so that systems installed without a configured time zone show an obviously unset value instead of a wrong one.

Rule for future years (POSIX TZ string)

<-00>0

The standard time is called “-00” (a numeric abbreviation) and is UTC+0. POSIX writes the offset with the opposite sign (west of Greenwich is positive), which is why the string says "0". There is no daylight saving rule: the zone stays on this offset for every year after the end of its explicit transitions. Software that has no full tzdata copy, such as many embedded devices, can use this string directly as the TZ environment variable.

History of Factory since 1970

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

Other zones that keep exactly the same time under the current rules (but have a different history): Africa/Abidjan, Africa/Bissau, Africa/Casablanca, Africa/El_Aaiun, Africa/Monrovia, Africa/Sao_Tome, America/Danmarkshavn.

Convert Factory time

Using Factory 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: 'Factory' })

# Python 3.9+
from zoneinfo import ZoneInfo
from datetime import datetime
datetime.now(ZoneInfo('Factory'))

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

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

-- PostgreSQL
SELECT now() AT TIME ZONE 'Factory';

# Shell
TZ='Factory' 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.

Related

• Time zones of the world
• UTC time
• Daylight saving time