Free Time Tool

Time Zone Converter
Convert 400+ World Time Zones

Instantly convert times between 400+ world time zones — with DST awareness, bulk input, file upload, and CSV download. Free, no login needed.

Convert Time Zone Now
400+
Time Zones
DST
Aware Conversion
Bulk
Multi-Line Input
Free
No Login Needed

Bulk Time Zone Converter

Enter timestamps below (one per line) or upload a .txt/.csv file. All times are converted from the source zone to the target zone simultaneously.

Click to upload or drag & drop a .txt or .csv file containing timestamps

Supports .txt/.csv files up to 2MB

Conversion Result
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Converted
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Why Use Our Tool

Advanced Time Zone Converter Features

The most comprehensive free time zone tool — DST-aware, accurate, and built for both quick single conversions and large batch processing.

400+ Time Zones

Full IANA time zone database — covering every country, territory, and region in the world. Search by city, region, or UTC offset for fast selection.

DST-Aware

Automatically accounts for Daylight Saving Time transitions based on the exact date of your input. No manual offset adjustment required — ever.

Bulk Conversion

Convert dozens of timestamps at once — one per line. Ideal for meeting schedulers, log analysts, travel planners, and software developers working across time zones.

File Upload Support

Upload a .txt or .csv file containing your timestamps. Drag and drop or click to browse — supports files up to 2MB for large-scale batch conversions.

Live World Clocks

See real-time clocks for major cities — New York, London, Dubai, Mumbai, Singapore, Tokyo — updating live every second at the top of the tool.

CSV & TXT Download

Download conversion results as a structured CSV file — perfect for import into spreadsheets, scheduling tools, or time-tracking software.

Simple Process

How to Convert Between Time Zones

Convert timestamps between any world time zones in four simple steps — no software installation required.

1

Enter Timestamps

Paste timestamps into the input box (one per line) or upload a .txt/.csv file. Supported formats include YYYY-MM-DD HH:MM, ISO 8601, and more.

2

Select Time Zones

Choose the source time zone (From) and target time zone (To) from the dropdown. Search by city name or UTC offset for fast selection.

3

Click Convert

Hit "Convert Time Zone" and the tool instantly converts each timestamp, handling DST transitions and UTC offsets automatically.

4

Copy or Download

Copy results to clipboard or download as CSV or TXT. Per-line mode shows UTC offset, DST status, and day-change indicators for each result.

What Is a Time Zone? How Time Zone Conversion Works & Why It Matters

A time zone is a geographic region that observes a uniform standard time for legal, commercial, and social coordination. The world is divided into 24 primary time zones, each offset from UTC (Coordinated Universal Time) by a whole or fractional number of hours. For example, New York operates at UTC−5 (EST) in winter and UTC−4 (EDT) during summer Daylight Saving Time, while India uses UTC+5:30 year-round with no DST. Understanding this interplay of offsets and DST rules is essential for anyone coordinating across borders.

How does time zone conversion work? Every timestamp can be expressed as a UTC value — an absolute moment in time independent of geography. Converting between time zones involves converting the source time to UTC, then adding the target zone's offset. For example, 9:00 AM EST (UTC−5) = 14:00 UTC = 7:30 PM IST (UTC+5:30). Our tool performs this arithmetic automatically, accounting for DST transitions on the exact date of your input using the full IANA time zone database.

What is Daylight Saving Time (DST)? DST is the practice of advancing clocks by one hour during warmer months to extend evening daylight. It is observed in approximately 70 countries including most of North America and Europe. DST start and end dates differ by country — in the US, clocks spring forward on the second Sunday in March and fall back on the first Sunday in November. Failing to account for DST is a common cause of missed meetings and scheduling errors across time zones.

Who uses a time zone converter? Remote teams scheduling cross-continental meetings, travel planners booking international flights, software developers logging events with correct local times, financial traders tracking market open/close times, and anyone managing global operations. Our bulk converter processes entire spreadsheets of timestamps in one pass — saving hours of manual offset calculation.

Key time zones to know: UTC±0 (London/GMT), UTC−5 (New York EST), UTC−8 (Los Angeles PST), UTC+1 (Paris CET), UTC+3 (Dubai), UTC+5:30 (Mumbai IST), UTC+8 (Singapore/Beijing CST), UTC+9 (Tokyo JST), UTC+10 (Sydney AEST). This tool converts between all of them — and hundreds more — instantly and for free.

FAQ

Frequently Asked Questions

Everything you need to know about time zone conversion.

A time zone is a region of the Earth that observes a uniform standard time defined by its offset from UTC. There are 24 primary time zones plus many partial-hour zones like India (UTC+5:30) and Nepal (UTC+5:45). Some regions further adjust clocks seasonally with Daylight Saving Time.
Enter your timestamp and select source and target time zones. The tool converts the input to UTC, then applies the target zone's offset — including any DST shift for the specific date. Results show the converted time, UTC offset, and DST status.
DST (Daylight Saving Time) shifts clocks by +1 hour in spring and back in autumn in regions that observe it. This tool uses the JavaScript Intl API and the full IANA time zone database to automatically apply the correct DST offset for every date and zone combination, so you never have to adjust manually.
Supported formats: YYYY-MM-DD HH:MM, YYYY-MM-DD HH:MM:SS, MM/DD/YYYY HH:MM, ISO 8601 (YYYY-MM-DDTHH:MM:SS), and time-only (HH:MM, treated as today's date). 12-hour (AM/PM) and 24-hour output are both supported.
Yes. Enter one timestamp per line in the text area and all lines are converted simultaneously. You can also upload a .txt or .csv file for large-scale batch conversions. Download results as CSV for import into scheduling or planning tools.
UTC (Coordinated Universal Time) is the modern, atomic-clock-based time standard. GMT (Greenwich Mean Time) is an older time zone based on solar observation. They share the same offset (UTC±0) but are technically distinct — UTC is the international standard used in computing, while GMT is a legacy time zone still used colloquially.
Yes, completely free with no registration required. All conversions run in your browser using JavaScript and the Intl API — no data is sent to any server. Your timestamps never leave your device.
EST (Eastern Standard Time, UTC−5) is 10 hours and 30 minutes behind IST (India Standard Time, UTC+5:30). So 9:00 AM EST = 7:30 PM IST. During US DST (EDT, UTC−4), the difference reduces to 9 hours 30 minutes. Select "America/New_York" and "Asia/Kolkata" in the converter above to verify any specific time.

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