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Time Zone Converter Examples
The Time Zone Converter converts times between time zones around the world, handling daylight saving time automatically. Below are practical examples for scheduling meetings, working with APIs, and coordinating distributed teams.
Common Time Zone Conversions
// UTC to major cities (standard time, no DST):
UTC 12:00 (noon) =
New York (EST): 07:00 (UTC-5)
London (GMT): 12:00 (UTC+0)
Paris (CET): 13:00 (UTC+1)
Dubai (GST): 16:00 (UTC+4)
Mumbai (IST): 17:30 (UTC+5:30)
Singapore (SGT): 20:00 (UTC+8)
Tokyo (JST): 21:00 (UTC+9)
Sydney (AEDT): 23:00 (UTC+11)
Daylight Saving Time (DST) Impact
// New York during DST (summer, EDT = UTC-4):
UTC 12:00 → New York: 08:00 (EDT, UTC-4)
// New York during standard time (winter, EST = UTC-5):
UTC 12:00 → New York: 07:00 (EST, UTC-5)
// DST transition dates (US, 2024):
Spring forward: March 10, 2024 at 2:00 AM → 3:00 AM
Fall back: November 3, 2024 at 2:00 AM → 1:00 AM
// Europe DST transition (2024):
Spring forward: March 31, 2024
Fall back: October 27, 2024
// Note: Not all countries observe DST
// No DST: Japan, China, India, most of Africa
IANA Time Zone Identifiers
// Use IANA names for unambiguous time zone identification:
America/New_York // Eastern US (handles EST/EDT automatically)
America/Chicago // Central US (CST/CDT)
America/Denver // Mountain US (MST/MDT)
America/Los_Angeles // Pacific US (PST/PDT)
Europe/London // UK (GMT/BST)
Europe/Paris // France (CET/CEST)
Europe/Berlin // Germany (CET/CEST)
Asia/Tokyo // Japan (JST, no DST)
Asia/Shanghai // China (CST, no DST)
Asia/Kolkata // India (IST = UTC+5:30, no DST)
Asia/Kathmandu // Nepal (NPT = UTC+5:45, no DST)
Australia/Sydney // Eastern Australia (AEST/AEDT)
Pacific/Auckland // New Zealand (NZST/NZDT)
International Meeting Scheduling
// Find overlap for: New York, London, Singapore
// Business hours: 9:00 AM – 6:00 PM local time
// New York (EST, UTC-5): 9:00 AM – 6:00 PM
// London (GMT, UTC+0): 9:00 AM – 6:00 PM
// Singapore (SGT, UTC+8): 9:00 AM – 6:00 PM
// Overlap analysis:
// When it's 9 AM in New York (UTC 14:00):
// London: 2:00 PM ✓ (within business hours)
// Singapore: 10:00 PM ✗ (after hours)
// When it's 9 AM in London (UTC 09:00):
// New York: 4:00 AM ✗ (too early)
// Singapore: 5:00 PM ✓ (within business hours)
// Best overlap window:
// London 2:00 PM – 6:00 PM (UTC 14:00–18:00)
// New York 9:00 AM – 1:00 PM
// Singapore 10:00 PM – 2:00 AM (late for Singapore)
// Conclusion: No perfect overlap — schedule at 9 AM NY / 2 PM London
// and accept that Singapore joins at 10 PM
JavaScript Time Zone Conversion
// Convert a UTC time to a specific timezone
const date = new Date('2024-03-15T14:00:00Z');
// Format in different timezones
const options = { timeZone: 'America/New_York', hour12: false,
year: 'numeric', month: '2-digit', day: '2-digit',
hour: '2-digit', minute: '2-digit' };
date.toLocaleString('en-US', { timeZone: 'America/New_York' });
// "3/15/2024, 10:00:00 AM"
date.toLocaleString('en-GB', { timeZone: 'Europe/London' });
// "15/03/2024, 14:00:00"
date.toLocaleString('ja-JP', { timeZone: 'Asia/Tokyo' });
// "2024/3/15 23:00:00"
// Using Intl.DateTimeFormat
const formatter = new Intl.DateTimeFormat('en-US', {
timeZone: 'America/Los_Angeles',
dateStyle: 'full',
timeStyle: 'long'
});
formatter.format(date);
// "Friday, March 15, 2024 at 7:00:00 AM PDT"
Unix Timestamp to Local Time
// Unix timestamp: 1710504000 (2024-03-15 14:00:00 UTC)
// Convert to different timezones:
UTC: 2024-03-15 14:00:00 UTC
New York (EDT): 2024-03-15 10:00:00 EDT (UTC-4, DST active)
London (GMT): 2024-03-15 14:00:00 GMT
Paris (CET): 2024-03-15 15:00:00 CET
Tokyo (JST): 2024-03-15 23:00:00 JST
Sydney (AEDT): 2024-03-16 01:00:00 AEDT (next day!)
API Timestamp Best Practices
// Always store and transmit timestamps in UTC
// Use ISO 8601 format with explicit UTC indicator
// Good:
"createdAt": "2024-03-15T14:00:00Z" // Z = UTC
"createdAt": "2024-03-15T14:00:00+00:00" // explicit UTC offset
// Avoid:
"createdAt": "2024-03-15 14:00:00" // no timezone — ambiguous
"createdAt": "March 15, 2024 2:00 PM" // locale-specific format
// Convert to local time only for display:
const utcTime = "2024-03-15T14:00:00Z";
const localTime = new Date(utcTime).toLocaleString();
World Clock Reference (UTC 12:00)
City | Time Zone | UTC Offset | Local Time
------------------|------------------|------------|----------
Los Angeles | America/LA | UTC-8/-7 | 04:00/05:00
New York | America/NY | UTC-5/-4 | 07:00/08:00
São Paulo | America/Sao_Paulo| UTC-3 | 09:00
London | Europe/London | UTC+0/+1 | 12:00/13:00
Paris | Europe/Paris | UTC+1/+2 | 13:00/14:00
Dubai | Asia/Dubai | UTC+4 | 16:00
Mumbai | Asia/Kolkata | UTC+5:30 | 17:30
Singapore | Asia/Singapore | UTC+8 | 20:00
Tokyo | Asia/Tokyo | UTC+9 | 21:00
Sydney | Australia/Sydney | UTC+10/+11 | 22:00/23:00
Common Use Cases
- Schedule international meetings across multiple time zones
- Convert API timestamps to local time for display
- Plan deployment windows that avoid peak hours globally
- Understand when business hours overlap between offices
- Convert log timestamps from server UTC to local time
- Calculate deadlines across time zones
- Verify DST transition handling in date/time code
Enter a time and select your source and target time zones to get an instant, DST-aware conversion.