America/Mexico_City time zone
8:02AMCST
CSTUTC−6−1 h vs New York (you)
No transitions: America/Mexico_City stays on CST (UTC−6).
About America/Mexico_City
America/Mexico_City is the IANA time zone for Central Mexico in Mexico. It currently keeps Central Standard Time (CST, UTC−6) all year.
Its principal location is Mexico City at 19.40° N, 99.15° W.
Abbreviations in use: CST. Offset page: UTC−6.
Rule for future years (POSIX TZ string)
CST6
The standard time is called CST and is UTC−6. POSIX writes the offset with the opposite sign (west of Greenwich is positive), which is why the string says "6". 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 America/Mexico_City since 1970
The record starts with local mean time (UTC−6:37), which ended on January 1, 1922. The first daylight saving time in the record is in 1931.
| Years | Clocks | Abbreviations |
|---|---|---|
| 1970–1995 | UTC−6 all year | CST |
| 1996–2022 | UTC−6 in winter, UTC−5 in summer | CST, CDT |
| 2023 onward | UTC−6 all year | CST |
Before 1970
14 offset changes before 1970 in the record:
- Sunday, January 1, 1922: UTC−6:37 → UTC−7 (MST)
- Friday, June 10, 1927: UTC−7 → UTC−6 (CST)
- Saturday, November 15, 1930: UTC−6 → UTC−7 (MST)
- Thursday, April 30, 1931: UTC−7 → UTC−6 (MDT), daylight saving time
- Thursday, October 1, 1931: UTC−6 → UTC−7 (MST)
- Friday, April 1, 1932: UTC−7 → UTC−6 (CST)
- Sunday, February 5, 1939: UTC−6 → UTC−5 (CDT), daylight saving time
- Sunday, June 25, 1939: UTC−5 → UTC−6 (CST)
- Monday, December 9, 1940: UTC−6 → UTC−5 (CDT), daylight saving time
- Tuesday, April 1, 1941: UTC−5 → UTC−6 (CST)
- Thursday, December 16, 1943: UTC−6 → UTC−5 (CWT), daylight saving time
- Monday, May 1, 1944: UTC−5 → UTC−6 (CST)
- Sunday, February 12, 1950: UTC−6 → UTC−5 (CDT), daylight saving time
- Sunday, July 30, 1950: UTC−5 → UTC−6 (CST)
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 America/Mexico_City in tzdata. Their pages redirect here: Mexico/General.
Other zones that keep exactly the same time under the current rules (but have a different history): America/Bahia_Banderas, America/Belize, America/Chihuahua, America/Costa_Rica, America/Edmonton, America/El_Salvador, America/Guatemala, America/Inuvik, America/Managua, America/Merida, America/Monterrey, America/Regina.
Places on America/Mexico_City
Convert Mexico City time
Using America/Mexico_City 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: 'America/Mexico_City' })
# Python 3.9+
from zoneinfo import ZoneInfo
from datetime import datetime
datetime.now(ZoneInfo('America/Mexico_City'))
// Java
java.time.ZonedDateTime.now(java.time.ZoneId.of("America/Mexico_City"))
// Go
loc, _ := time.LoadLocation("America/Mexico_City")
time.Now().In(loc)
-- PostgreSQL
SELECT now() AT TIME ZONE 'America/Mexico_City';
# Shell
TZ='America/Mexico_City' datePlatforms 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.