Time Zone Converter & Meeting Planner

About this tool

This time zone converter takes one date and time in a source zone and shows it in as many other zones as you like, with the date shift, the UTC offset and the local abbreviation for each. A meeting planner underneath lines up every hour of the day across all your zones and highlights the hours that fall inside everyone's working day. It uses the IANA time zone database built into your browser, so daylight saving time is applied for the exact date you pick, and nothing is sent to a server. There is no sign-up and no limit on zones.

How to use the time zone converter

1. Pick the date and time you want to convert, or press Now to load the current time in the source zone.
2. Choose the source zone. Type a city, country or abbreviation such as Chicago, India or EST in the search box to narrow the list, or press Use my time zone.
3. Read the table. Each row shows the local time, the date (with +1 day or -1 day when the date changes), the UTC offset in force on that date, and the abbreviation with its full name.
4. Add or remove zones. Search for any zone and press Add zone; use Remove on a row to drop it. Reset to default zones brings back the starting list.
5. Plan a meeting. Set working hours, then scan the strip for the darkest columns, which suit every zone. The sentence above the strip names the best hours.

How time zones, UTC offsets and DST work

Every civil time zone is defined by its offset from Coordinated Universal Time (UTC). New York in winter is UTC-05:00, so 2:00 PM UTC is 9:00 AM there. India is UTC+05:30 all year, which is why Indian times often end in :30 when converted. To convert between two zones you only need each zone's offset at that instant: the difference between the offsets is the difference between the clocks.

The complication is daylight saving time (DST). Many zones move their clocks forward an hour in spring and back in autumn, so their offset changes during the year, and different countries switch on different dates. That is why the gap between two cities can be 5 hours one week and 4 the next. This tool never stores offsets. For every row it asks the browser's copy of the IANA tz database what the offset is at that exact moment, which also covers past rule changes recorded in that database.

US and European daylight saving rules

In the United States, the Energy Policy Act of 2005 set DST to begin at 2:00 a.m. local time on the second Sunday of March and end at 2:00 a.m. on the first Sunday of November (15 U.S.C. 260a; NIST). NIST notes that DST is not observed in Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and the state of Arizona, with the Navajo Nation in Arizona the exception: it does observe DST. Choose America/Phoenix for most of Arizona and America/Denver for the Navajo Nation.

In the European Union, Directive 2000/84/EC starts summer time at 1:00 a.m. GMT on the last Sunday in March and ends it at 1:00 a.m. GMT on the last Sunday in October, so every EU country switches at the same instant. The UK uses the same Sundays (GOV.UK). Because the US starts earlier and finishes later, transatlantic gaps shrink by an hour for a few weeks each spring and autumn. These dates come from Python's zoneinfo:

Times that do not exist or happen twice

On the spring-forward date, New York clocks go from 1:59 AM straight to 3:00 AM, so 2:30 AM never happens. If you enter a missing time, the converter reads it with the offset in force just before the jump, which moves it forward by the size of the gap: 2:30 AM on Sunday, March 8, 2026 is treated as 3:30 AM EDT, and a note explains this. On the fall-back date the hour from 1:00 to 1:59 AM happens twice, first in EDT and then in EST. The converter shows the first occurrence and offers a checkbox to switch to the second. This matches how Python's zoneinfo resolves the same inputs by default.

Worked example

The tool opens at 9:00 AM on today's date in New York with seven zones. On a summer date such as July 15, 2026 it shows 8:00 AM CDT in Chicago, 7:00 AM MDT in Denver, 6:00 AM PDT in Los Angeles, 1:00 PM UTC, 2:00 PM BST in London and 6:30 PM IST in India. On a winter date such as January 15, 2026 the US rows read EST, CST, MST and PST with the same clock times, UTC moves to 2:00 PM, London shows 2:00 PM GMT, and India shows 7:30 PM, because India has no DST. With 9 AM to 5 PM working hours no single hour suits all seven zones; the planner reports a best fit of 5 of 7 zones from 11:00 AM to 1:00 PM EDT in July, and from 11:00 AM to 12:00 PM EST in January.

Abbreviations are ambiguous

Three-letter abbreviations are labels, not identifiers. IST can mean India Standard Time, Irish Standard Time or Israel Standard Time, and CST is used for both US Central Standard Time and China Standard Time. That is why this tool lists every zone by its IANA name, such as Asia/Kolkata or Europe/Dublin, and shows the full name next to each abbreviation. When you schedule something, write the city or the UTC offset, not just three letters.

Common mistakes

• Writing "EST" or "PST" in summer, when the clocks actually read EDT or PDT. Writing ET or PT avoids the issue.
• Assuming the gap between two cities is fixed. New York to London is usually 5 hours, but 4 for a few weeks in March and around late October.
• Forgetting the date. A 6:00 PM call in California is already the next morning in India.
• Treating GMT and UK time as the same thing all year. London is on BST (UTC+1) in summer.

Use cases

• Finding a meeting slot for a team split between the US, Europe and India.
• Checking what time a webinar, product launch or sports event starts where you live.
• Converting log timestamps between UTC and local time while debugging.

For a single pair of zones, the dedicated converters have printable hour-by-hour charts: PST to EST, CST to EST, UTC to EST, GMT to EST, UTC to PST, EST to IST. To convert Unix timestamps, use the Timestamp Converter; to count the hours between two times, try the Time Duration Calculator.