Convert any date and time between world timezones instantly. Covers 30+ cities across all regions with DST support. Free online timezone converter for developers and remote teams.
Target Timezones
Timezone Converter is a free online tool that converts any date and time between world timezones with full Daylight Saving Time support. Select a source date, time, and timezone, choose any combination of target timezones from 30+ major cities worldwide, and instantly see the equivalent local time in each location. All conversions use IANA timezone identifiers, ensuring DST transitions are applied correctly for the specific date you enter.
Use Timezone Converter when scheduling international meetings across multiple time zones, verifying that a server-side scheduled job fires at the right local time in each region, debugging UTC timestamps in logs, coordinating deployments across globally distributed teams, or confirming what time an event occurring in another timezone corresponds to in your local time.
Remote engineering teams use Timezone Converter to schedule stand-ups and sprint reviews that work for members across multiple continents. DevOps engineers use it to verify cron job run times in production regions. Product managers use it to coordinate launches and announcements across global markets. Developers use it to debug timezone-related bugs in application logs and to understand how UTC timestamps translate to local user times in their supported regions.
Essential terms and definitions related to Timezone Converter.
A publicly maintained database of all historical and current timezone rules worldwide, using location-based identifiers like "America/New_York" or "Asia/Tokyo". Unlike timezone abbreviations (EST, IST), IANA identifiers are unambiguous and encode DST rules, allowing software to correctly calculate time at any past or future date. Used by operating systems, browsers, and programming languages as the authoritative timezone reference.
The primary global time standard that all other timezones are defined as offsets from. UTC does not observe Daylight Saving Time and never changes. It is the successor to GMT (Greenwich Mean Time), which it replaced in 1972 for scientific purposes. In most practical contexts, UTC and GMT are interchangeable. All timestamps should ultimately be stored and communicated in UTC.
The practice of advancing clocks by one hour during warmer months (spring/summer) to shift an hour of daylight from the morning to the evening. Not all countries observe DST: most of Asia, Africa, and South America do not. Countries that do observe DST transition on different dates, creating a period where time differences between regions temporarily change by one hour.
The difference in hours and minutes between a timezone and UTC. For example, UTC+5:30 means the local time is 5 hours and 30 minutes ahead of UTC. Offsets can be fractional (India is +5:30, Nepal is +5:45, Iran is +3:30). UTC offsets change for timezones that observe DST — for example, "America/New_York" is UTC-5 in winter and UTC-4 in summer.
Yes. The converter uses the browser's native Intl API with IANA timezone identifiers (e.g., "America/New_York" instead of "EST"), which automatically applies the correct DST offset for the specific date and time you entered. A date in July will use EDT (UTC-4), while the same city in January will use EST (UTC-5). This makes the tool accurate across DST transitions without any manual adjustment.
A UTC offset (like UTC+3) is a fixed number of hours ahead of or behind UTC. A timezone (like "Europe/Istanbul") is a named region that may change its UTC offset throughout the year due to Daylight Saving Time. UTC+3 is always 3 hours ahead of UTC, but Europe/Istanbul is UTC+3 in winter and UTC+3 year-round (Turkey stopped DST in 2016). Always use IANA timezone names for scheduling to avoid DST bugs.
DST transitions happen on different dates in different countries. The US "springs forward" on the second Sunday in March, while Europe changes on the last Sunday in March. During the gap between these dates, the time difference between US and European cities changes by one hour. When scheduling recurring meetings across DST boundaries, always confirm in both parties' local times. Using UTC for scheduling and converting to local time at display avoids DST confusion entirely.
Select the city from the source or target timezone list, enter the current date and time, and look at the result row for that city. The time zone abbreviation shown (e.g., EST, CEST, JST) indicates the current offset. Alternatively, the UTC row always shows the source time converted to UTC, which lets you calculate the offset manually.
IST is ambiguous and can mean Indian Standard Time (UTC+5:30), Irish Standard Time (UTC+1, summer only), or Israeli Standard Time (UTC+2, summer only). This is why IANA timezone identifiers like "Asia/Kolkata" for India and "Europe/Dublin" for Ireland are unambiguous. Always use IANA names in code — abbreviations like IST, CST, and EST are not standardized and can mean different things in different regions.
Store all timestamps in UTC. When writing to the database, convert user local time to UTC first. When reading, convert from UTC to the user's local timezone for display. Storing in UTC means the stored value is unambiguous regardless of DST changes or the user's location. Use the Unix timestamp (seconds or milliseconds since epoch) or an ISO 8601 string with a Z suffix (e.g., 2024-01-15T14:30:00Z) for maximum portability across systems and languages.
Common errors developers encounter and how to resolve them.
Conversion result is off by one hour This is almost always a Daylight Saving Time issue. The source or target timezone is in a DST transition period and the offset has changed. Verify the date you entered — a date before or after the DST transition date will use a different offset. Using IANA timezone names (as this tool does) should handle this automatically. If the error persists, check whether your browser's timezone database is up to date.
Timezone not in the list The tool includes 30+ major cities covering all UTC offsets. If your specific city is not listed, select another city in the same timezone — for example, for São Paulo time use "São Paulo (BRT)", and for cities sharing the same offset like Melbourne, use "Melbourne (AEST/AEDT)". All cities within the same IANA timezone region observe the same DST rules.
Date changes when converting (different day in target timezone) This is expected. When it is 11 PM in New York, it is already the next day morning in Tokyo. The converter correctly shows the date change. The day boundary crossing is not an error — it is a natural consequence of timezones spanning 25+ hours from UTC-12 to UTC+14.