Worldwide Time Zone Database
Search over 500+ global cities and standard IANA time zones (UTC, EST, PST, GMT, CET, JST, etc.).
Time Zone Converter
Time Zone & World Clock Converter
Check current local times, calculate exact time differences between countries, and compare world clocks.
Time Difference Comparison
🇻🇳 Hanoi is 11 hours behind 🇺🇸 New York
(Previous Day)Vietnam (UTC/GMT+7) vs United States (UTC/GMT-4)
🇻🇳
UTC/GMT+7Hanoi
Vietnam
Day Time
08:59 AM
Sun, Nov 1, 2026
🇺🇸
UTC/GMT-4New York
United States
Night Time
09:59 PM
Sat, Oct 31, 2026
Device settings · Remembering on
Only preferences are remembered, not your files or input. Turn off to delete saved preferences.
How It Works & Methodology
A time zone is a geographical region where the same standard time is enforced for legal, commercial, and social purposes. Earth is divided into 24 standard time zones based on the 360-degree rotation of the planet (approx. 15° of longitude per 1-hour interval).
Coordinated Universal Time (UTC) is the primary time standard by which the world regulates clocks and time. Local times are expressed as positive or negative offsets from UTC (e.g., UTC+7 for Vietnam and Thailand, UTC-5 for US Eastern Standard Time).
Daylight Saving Time (DST) Explained
Daylight Saving Time (DST) is the practice of advancing clocks (typically by one hour) during warmer months so that darkness falls at a later clock time. Clocks are adjusted forward ("spring forward") in spring and set back ("fall back") to standard time in autumn.
Because different countries (and even different regions within a single country) begin and end DST on different dates—or choose not to observe DST at all—time differences between two locations can shift by an hour throughout the year.
Non-Standard & Fractional Time Zones
While most time zones differ from UTC by whole hours, several countries utilize 30-minute or 45-minute fractional offsets to better align solar noon with clock time. Notable examples include India and Sri Lanka (UTC+5:30), Iran (UTC+3:30), Afghanistan (UTC+4:30), Nepal (UTC+5:45), Myanmar (UTC+6:30), and Central Australia (UTC+9:30).
Frequently Asked Questions
How to use Time Zone Converter
- 1
Select your origin city or time zone and set the reference date and time.
- 2
Add one or more destination cities or time zones to compare.
- 3
View converted times side-by-side with daylight saving time (DST) adjustments.
Why use this tool?
Automatic Daylight Saving Time
Calculates historical and current DST time offsets accurately using browser Intl time zone data.
Meeting Planner View
Color-coded working hours make it easy to find overlapping business hours across countries.
Frequently asked questions
Does this tool account for Daylight Saving Time (DST)?
Yes. It automatically adjusts for DST changes according to each regions official schedule.
Can I compare multiple international cities simultaneously?
Yes. You can add as many cities as you need to compare international team working hours.
How do I find overlapping work hours for a meeting?
Use the interactive time slider to see business hours highlighted across all selected cities.
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