Convert any date and time between IANA time zones with correct daylight-saving handling and explicit offsets.
The time zone converter translates a date and time from one place on Earth to another — and to UTC — using IANA time-zone identifiers such as Europe/Warsaw or America/New_York, never ambiguous abbreviations like "CST" that mean different things in different countries. You pick the source zone, the date and time, and the target zone; the converter returns the equivalent time in the target zone, the UTC instant, and the UTC offset of both zones at that moment. Daylight-saving transitions are handled by the browser’s own time-zone data: on a spring-forward day, a local time that does not exist (for example 02:30 in a zone that skipped 02:00–03:00) is resolved by the standard convention of shifting forward, and the page says so explicitly rather than pretending the time exists. On a fall-back day, an ambiguous local time resolves to the earlier offset. Everything runs locally in your browser — the dates you enter never leave your device and are never logged. Use this converter for scheduling across time zones, checking what "9 AM your time" means in the client’s city, and verifying timestamps in logs and exports.
Processed locally in your browser
Target time
—
UTC instant
—
Source offset
—
Target offset
—
Offsets are computed at the exact instant being converted. On DST transition days, a
nonexistent local time is shifted forward and flagged above.
How is the result calculated?
Scheduling with a client: 14:00 Warsaw → New York
A 14:00 meeting in Warsaw (Europe/Warsaw, UTC+2 in summer) is 12:00 UTC — and 08:00 in New York (America/New_York, UTC−4 in summer). The converter shows all three at once: the target time, the UTC instant, and the offsets, so the invitation can be double-checked instead of guessed.
Example input and output
Input
Value
date
2026-08-04
time
14:00
from
Europe/Warsaw
to
America/New_York
Result
08:00 America/New_York · 12:00 UTC · Warsaw UTC+02:00 · New York UTC−04:00
What is the formula and its assumptions?
Conversion method
target time = source wall time − source offset + target offset
Formula terms
Symbol
Meaning
source offset
UTC offset of the source zone at that instant
target offset
UTC offset of the target zone at that instant
Offsets are read from the IANA time-zone database at the specific instant, so DST transitions on either side are handled correctly.
Offsets
offset(zone, instant) = local wall time − UTC time, in minutes
Formula terms
Symbol
Meaning
instant
the exact moment being converted
What are the most common mistakes?
Using fixed abbreviations that change meaning between regions or seasons.
Assuming the offset of a zone is constant across the year — DST changes it.
Converting with the wrong date: the offset depends on the specific day, not just the hour.
What are the assumptions and limitations?
The converter uses your browser’s embedded IANA data — extremely rare future rule changes require a browser update to be reflected.
Historical time-zone changes before the database’s coverage are resolved with the closest known rules.
The converter works with a single instant; recurring meetings across DST boundaries need the meeting-overlap planner.
Abbreviations are ambiguous — "CST" is Central Standard Time, China Standard Time, and Cuba Standard Time. IANA identifiers like America/Chicago name one zone unambiguously, which is why this converter only uses them.
What happens to a time that does not exist locally (spring forward)?
The converter uses the standard convention: the local time shifts forward by the skipped hour (for example 02:30 becomes 03:30). The page flags this so the result is never silently surprising.
Does the converter know the current offset?
It computes the offset at the exact instant you convert, not a fixed offset — so a date in January and a date in July can have different offsets for the same zone, which is exactly how DST works.