Timezone Converter
Time & SpeedConvert time between any two timezones instantly — IST, UTC, EST, GMT, SGT, JST, and 20+ more. Handles DST automatically. Free, in-browser, no sign-up.
18 Jun 2026, 10:30:00 am GMT-4
ISO 86012026-06-18T10:30:00
UTC18 Jun 2026, 02:30:00 pm UTC
What is a Timezone?
A Timezone Converter takes a date and time in one timezone and shows the equivalent moment in another timezone. The underlying time (the UTC moment) does not change — only the local clock representation changes based on the timezone offset.
Timezones are defined by offsets from UTC, ranging from UTC−12 to UTC+14. India Standard Time (IST) is UTC+5:30. When it is 12:00 noon in Mumbai, it is simultaneously 6:30 AM in London (UTC+0 in winter), 1:30 AM in New York (UTC−5 in winter), and 3:30 PM in Singapore (UTC+8). The converter handles all of these translations — including Daylight Saving Time adjustments — automatically.
The converter covers 25 timezones across Asia, Europe, the Americas, and the Pacific, with particular emphasis on zones relevant to Indian users: IST, GST (Dubai), SGT (Singapore), JST (Tokyo), and the major US time zones. DST transitions are handled automatically via the browser's IANA timezone database — you do not need to know whether a date falls in summer or winter time.
For converting Unix timestamps (epoch seconds) to human-readable dates, use the Unix Timestamp Converter. For time duration conversions (hours to minutes, etc.), use the Time Converter.
How to use this Timezone calculator
- Enter the Date & Time in the input field — it defaults to the current local time.
- Select the From timezone — the zone the entered time is in.
- Select the To timezone — the zone you want to convert to.
- The converted time appears instantly below, with ISO and UTC outputs.
- Click ⇄ to reverse the conversion (swap From and To).
- Copy the ISO 8601 output for use in calendar invites, code, or email.
Formula & Methodology
UTC conversion: Given a datetime and source timezone, the browser'sIntl.DateTimeFormatAPI resolves the IANA timezone rules for that specific date (accounting for DST transitions) to compute the UTC offset. The converter applies this offset to find the underlying UTC timestamp. Display conversion: The UTC timestamp is then formatted in the target timezone usingIntl.DateTimeFormatwithtimeZone: targetTz, producing the local time representation including the correct DST-adjusted offset. Common IST conversions (winter, no DST): | IST (UTC+5:30) | UTC | ET (UTC−5) | PT (UTC−8) | SGT (UTC+8) | JST (UTC+9) | |---|---|---|---|---|---| | 9:00 AM | 3:30 AM | 10:30 PM (prev) | 7:30 PM (prev) | 11:30 AM | 12:30 PM | | 12:00 PM | 6:30 AM | 1:30 AM | 10:30 PM (prev) | 2:30 PM | 3:30 PM | | 6:00 PM | 12:30 PM | 7:30 AM | 4:30 AM | 8:00 PM | 9:30 PM | | 10:00 PM | 4:30 PM | 11:30 AM | 8:30 AM | 12:30 AM (+1) | 1:30 AM (+1) |
Frequently Asked Questions
How does the timezone converter handle Daylight Saving Time?
The converter uses the browser's built-in Intl.DateTimeFormat API, which applies the IANA timezone database. This means DST transitions are handled automatically — entering a date in summer will use the correct DST offset for that timezone, and entering a winter date will use the standard offset. You do not need to manually account for DST.
What is IST and what UTC offset does it use?
IST stands for India Standard Time, the timezone used across all of India (UTC+5:30). India does not observe Daylight Saving Time, so the offset is fixed year-round. IST is one of the few timezones with a half-hour offset — most timezones use whole-hour offsets. Nepal (UTC+5:45) is the only major timezone with a 45-minute offset.
What is UTC and why is it used as a reference?
UTC (Coordinated Universal Time) is the primary international time standard against which all other timezones are expressed as positive or negative offsets. It is the successor to GMT for most practical purposes. UTC is preferred in databases, APIs, logs, and server communications because it is unambiguous — it never changes for DST.
Why do some timezone labels show two offsets like UTC−5/−4?
Timezones that observe Daylight Saving Time shift their UTC offset by one hour between winter and summer. US Eastern Time is UTC−5 in winter (EST) and UTC−4 in summer (EDT). The label shows both values. The converter calculates the correct offset for the specific date and time you enter.
What is the best time to schedule a meeting between India and the US?
India Standard Time (IST, UTC+5:30) is 10 hours 30 minutes ahead of US Eastern Time in winter and 9 hours 30 minutes ahead in summer. A 9:00 AM ET meeting is 7:30 PM or 6:30 PM IST depending on the season. Early morning US time (7–9 AM ET) overlaps with IST business hours (5–7 PM IST) and is the most practical window for international calls.
Does the converter support all world timezones?
The converter includes 25 major timezones covering Asia, Europe, the Americas, and the Pacific. These cover the timezones most relevant to Indian users doing international work. For a niche timezone not in the list, use the UTC offset of that timezone to calculate manually from the UTC output shown.
Is my data stored or sent anywhere?
No. All conversions run entirely in your browser using the browser's built-in Intl.DateTimeFormat API. No datetime or location data is sent to a server.
What is the difference between GMT and UTC?
GMT (Greenwich Mean Time) and UTC are effectively the same for most purposes and share the same offset (UTC+0). The technical difference is that GMT is a timezone that can be adjusted for DST (in the UK, it becomes BST at UTC+1 in summer), while UTC is an atomic time standard that never adjusts. In common usage, GMT and UTC are interchangeable for the UTC+0 offset.
How do I convert IST to Singapore time?
Singapore Standard Time (SGT) is UTC+8. IST is UTC+5:30. The difference is 2 hours 30 minutes — Singapore is ahead. So 9:00 AM IST = 11:30 AM SGT. Enter the IST time in the converter with 'From' set to Asia/Kolkata and 'To' set to Asia/Singapore to get the exact converted time.
What timezone does Dubai use?
Dubai and the UAE use Gulf Standard Time (GST), which is UTC+4. There is no Daylight Saving Time in the UAE. IST (UTC+5:30) is 1 hour 30 minutes ahead of Dubai time. A flight departing Mumbai at 2:00 AM IST lands in Dubai (local time) at 3:30 AM GST — no DST adjustment needed.
Why does the converter show the date changing between timezones?
When converting across large timezone differences, the local date in the target timezone may differ from the source date. For example, 11:00 PM IST on Thursday converts to 12:30 PM ET on Thursday (US Eastern, UTC−5:30 difference = 10.5 hours behind). But 1:00 AM IST on Friday would convert to 2:30 PM ET on Thursday — the previous calendar day.