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America/Matamoros time zone

8:39AMCST

CSTUTC−6−1 h vs New York (you)

About America/Matamoros

America/Matamoros is the IANA time zone for Coahuila, Nuevo León, Tamaulipas (US border) in Mexico. It currently keeps Central Standard Time (CST, UTC−6) in winter and Central Daylight Time (CDT, UTC−5) in summer.

Its principal location is Matamoros at 25.83° N, 97.50° W.

Abbreviations in use: CST, CDT. Offset page: UTC−6.

Rule for future years (POSIX TZ string)

CST6CDT,M3.2.0,M11.1.0

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". Daylight saving time is called CDT and is UTC−5. It starts on the second Sunday of March at 02:00 and ends on the first Sunday of November at 02:00, 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 America/Matamoros since 1970

The record starts with local mean time (UTC−6:30), which ended on December 31, 1921. The first daylight saving time in the record is in 1988.

YearsClocksAbbreviations
1970–1987UTC−6 all yearCST
1988UTC−6 in winter, UTC−5 in summerCST, CDT
1989–1995UTC−6 all yearCST
1996 onwardUTC−6 in winter, UTC−5 in summerCST, CDT

Before 1970

1 offset change 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

Other zones that keep exactly the same time under the current rules (but have a different history): America/Chicago, America/Indiana/Knox, America/Indiana/Tell_City, America/Menominee, America/North_Dakota/Beulah, America/North_Dakota/Center, America/North_Dakota/New_Salem, America/Ojinaga, America/Rankin_Inlet, America/Resolute.

Convert Matamoros time

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

Using America/Matamoros 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/Matamoros' })

# Python 3.9+
from zoneinfo import ZoneInfo
from datetime import datetime
datetime.now(ZoneInfo('America/Matamoros'))

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

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

-- PostgreSQL
SELECT now() AT TIME ZONE 'America/Matamoros';

# Shell
TZ='America/Matamoros' 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 America/Matamoros?
UTC−6 in winter and UTC−5 in summer (daylight saving time from the second Sunday of March at 2:00 AM to the first Sunday of November at 2:00 AM).
Does America/Matamoros observe daylight saving time?
Yes: clocks move one hour forward on the second Sunday of March at 2:00 AM and back on the first Sunday of November at 2:00 AM.
Which countries use America/Matamoros?
Mexico, according to zone1970.tab in tzdata.

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