How do I convert time between time zones?

To convert a time, select the date and time in your 'Source' time zone. Then, add one or more 'Target' time zones you want to convert to. The calculator will instantly show you the corresponding local time in each target location, automatically accounting for Daylight Saving Time (DST).

What is DST and how does it affect conversions?

Daylight Saving Time (DST) is the practice of advancing clocks during warmer months so that darkness falls at a later clock time. This means a location's offset from UTC can change during the year. This calculator uses the browser's built-in Internationalization API (Intl) to automatically handle DST, ensuring conversions are accurate for any given date.

Can I plan a meeting across multiple zones?

Yes. The 'Meeting Planner' mode is designed for this. You set a proposed meeting time in your own time zone, then add participants by selecting their time zones. The tool generates a table showing what time the meeting will be for everyone, highlighting times that fall outside of typical working hours (e.g., 8 AM - 6 PM).

What are IANA time zone names vs abbreviations?

IANA (Internet Assigned Numbers Authority) time zone names are standardized identifiers in the format 'Area/Location', like 'America/New_York' or 'Asia/Kolkata'. They are unambiguous and account for DST rules. Abbreviations like EST, PST, or IST can be ambiguous as multiple regions might use them. This calculator uses IANA names for accuracy.

How do I handle overnight conversions?

The calculator handles overnight conversions automatically. When you convert a time, the result will always show the correct corresponding date for the target time zone. If a conversion crosses midnight, the date will be correctly displayed as the next day or the previous day.

Can I export my scheduled meeting times?

Yes. In the Meeting Planner, after you have scheduled times, you can use the 'Export CSV' button to download a file of the schedule, which can be opened in any spreadsheet program. There is also a 'Copy Summary' button to paste the information into an email or message.

Time Zone Calculator — Convert Times, Plan Meetings, & Handle DST

🕒 Time Zone Calculator

How Time Zones & DST Work

A time zone is a region of the globe that observes a uniform standard time for legal, commercial, and social purposes. For accuracy, computer systems use **IANA (Internet Assigned Numbers Authority) time zone names** like 'America/New_York' or 'Asia/Dubai'. These names are crucial because they automatically account for historical changes and, most importantly, **Daylight Saving Time (DST)**.

DST is the practice of advancing clocks during warmer months. This means a location's offset from Coordinated Universal Time (UTC) can change twice a year. For example, New York is UTC-5 during winter (EST) but shifts to UTC-4 during summer (EDT). A smart time zone calculator must know the exact date to apply the correct DST rule, which this tool does automatically using your browser's built-in internationalization features.

Converting Between Time Zones (Examples and Pitfalls)

When converting time, the key is to use a specific date and an unambiguous time zone name. For example, converting 2:00 PM on October 1st in 'Asia/Kolkata' (India) to 'Europe/London' is straightforward. Since India does not observe DST, it is always UTC+5:30. In October, London is on British Summer Time (BST), which is UTC+1. The difference is 4.5 hours, so the time in London would be 9:30 AM on the same day.

A common pitfall is during a DST transition. For example, on the day clocks 'spring forward', there is a "skipped" hour (e.g., 2:00 AM to 3:00 AM may not exist). When clocks 'fall back', an hour is repeated, creating an "ambiguous" time. This calculator will warn you if you select a time that is skipped or ambiguous, ensuring you avoid confusion.

Best Practices for Global Meeting Scheduling

Planning meetings across multiple time zones can be challenging. Here are some best practices:

Use a Visual Planner: Use a tool like our 'Meeting Planner' to see the proposed time in every participant's local zone. This avoids manual calculation errors.
Anchor to UTC: When communicating, it's often clearest to state the meeting time in UTC and let participants convert to their local time. For example, "The meeting is at 14:00 UTC".
Consider "Working Hours": Be mindful of your colleagues' work-life balance. The Meeting Planner highlights times that fall outside of typical business hours (e.g., 8 AM to 6 PM) to help you find a time that is reasonable for everyone.
Send Calendar Invites: Always send a digital calendar invitation. Calendar applications like Google Calendar or Outlook are excellent at handling time zone conversions automatically for the recipient.

FAQ

Why does the calculator use 'Asia/Kolkata' instead of 'IST'? Abbreviations like IST, EST, and PST can be ambiguous. For example, 'IST' can mean India Standard Time, Irish Standard Time, or Israel Standard Time. Using the full IANA name 'Area/City' is the only way to guarantee accuracy.
How does the calculator get its time zone data? It uses the modern browser's built-in `Intl` (Internationalization) API, which has access to a full and up-to-date IANA time zone database. This ensures high accuracy without needing to embed a large database in the page.
What if I don't know the IANA name? You can start typing a major city (e.g., "Paris", "Tokyo", "Sydney") and the input field will suggest the correct IANA name for you.