UTC Now & ISO 8601 / RFC 3339 Converter (Online)
Timezone Hub is a free online timezone converter and datetime formatter that helps developers,
teams, and travelers work with times across the globe. Get UTC now instantly or convert between
any timezone using ISO 8601 datetime, RFC 3339, Unix epoch timestamps, and custom formats.
Whether you're scheduling international meetings, coordinating remote teams, debugging API timestamps,
or processing spreadsheet data, our UTC now online tool provides instant conversions without
requiring registration. Convert individual datetimes, bulk-process CSV/Excel files, calculate time differences,
or add/subtract durations—all in your browser with complete privacy.
Features
- Live Display: View current time across multiple timezones simultaneously
- Timezone Converter: Convert between any two timezones with format options
- Spreadsheet Converter: Bulk convert CSV/Excel files with timezone data
- Duration Calculator: Calculate time differences and add/subtract time
- Calendar Picker: Visual datetime selection with timezone awareness
Supported Formats
- ISO 8601: 2025-11-09T14:30:00Z
- RFC 3339: 2025-11-09T14:30:00+00:00
- Unix Epoch: 1731159000 (seconds) or 1731159000000 (milliseconds)
- Human Readable: November 9, 2025 2:30 PM UTC
- Custom Formats: Flexible date-fns formatting
Example Conversions
UTC to ISO 8601
Input: November 9, 2025 2:30 PM (UTC)
Output: 2025-11-09T14:30:00.000Z
ISO 8601 to RFC 3339
Input: 2025-11-09T14:30:00Z
Output: 2025-11-09T14:30:00+00:00
RFC 3339 to Unix Epoch
Input: 2025-11-09T14:30:00+00:00
Output: 1731159000 (seconds)
1731159000000 (milliseconds)
Timezone Conversion (EST to PST)
Input: 2025-11-09 14:30:00 (America/New_York, EST)
Output: 2025-11-09 11:30:00 (America/Los_Angeles, PST)
Quick Glossary
- UTC (Coordinated Universal Time)
- The primary time standard used worldwide, not affected by daylight saving time. Also known as Zulu time (Z).
- ISO 8601
- International standard for date and time representation. Format: YYYY-MM-DDTHH:mm:ss.sssZ
- RFC 3339
- Internet timestamp format, a profile of ISO 8601. Includes explicit timezone offset: YYYY-MM-DDTHH:mm:ss±HH:mm
- Unix Epoch / Unix Timestamp
- Number of seconds (or milliseconds) since January 1, 1970 00:00:00 UTC. Always in UTC.
- UTC Offset
- The difference in hours and minutes from UTC (e.g., +05:30 for India, -05:00 for EST).
- DST (Daylight Saving Time)
- Practice of advancing clocks during summer months. Affects timezone offsets (e.g., EST becomes EDT, PST becomes PDT).
- Zulu Time
- Military and aviation term for UTC. The "Z" suffix in ISO 8601 (e.g., 2025-11-09T14:30:00Z) means Zulu/UTC.
Common Use Cases
- API Development: Convert between timestamp formats for REST APIs, GraphQL, webhooks
- International Scheduling: Coordinate meetings across multiple timezones
- Remote Teams: Understand working hours for distributed team members
- Travel Planning: Calculate arrival times and adjust for timezone changes
- Data Processing: Normalize timestamps in CSV/Excel files for analysis
- Debugging: Parse and understand timestamps from logs, databases, APIs
- Time Calculations: Add or subtract durations, calculate time between events
Why Choose Timezone Hub?
- ✅ Free & No Registration: Use all features immediately without creating an account
- ✅ Privacy-First: All conversions happen in your browser; no data sent to servers
- ✅ Developer-Friendly: Supports all major datetime formats used in programming
- ✅ Bulk Processing: Convert entire CSV/Excel files with thousands of timestamps
- ✅ Mobile-Optimized: Works perfectly on phones, tablets, and desktops
- ✅ Open Source: Transparent, community-driven development
⚠️ JavaScript Required: This application requires JavaScript to run.
Please enable JavaScript in your browser settings to use the interactive timezone converter.