Time Zone Converter
Convert any time between two IANA time zones.
Common Time Zone Pairs
Click any row to convertCommon Time Zone Conversions
Standard (winter) offsets. DST adds +1 hour where applicable.
Understanding Time Zone Offsets
A UTC offset is simply the number of hours (and sometimes minutes) that a given location's clock is set ahead of or behind Coordinated Universal Time. An offset of UTC+5:30 means the clocks there read five hours and thirty minutes more than the time in UTC. Offsets are determined by a combination of geography - The Earth's 24 time zones correspond to 15-degree longitude slices - And political decisions made by each country's government.
Many countries adjust their clocks by one hour during summer months in a practice called Daylight Saving Time (DST). The goal is to shift an hour of morning daylight into the evening, reducing lighting costs and extending usable daytime for outdoor activity. When a country observes DST, its UTC offset changes - For example, the United Kingdom goes from UTC+0 in winter to UTC+1 in summer. This means the effective difference between two cities can vary by one hour depending on the time of year, and in some cases the change is not synchronized across borders. Browse the full time zones index to check DST status for any zone.
Not all time zones are whole-hour offsets. Several countries and regions have settled on non-standard offsets for geographic or historical reasons. Nepal (UTC+5:45) is unique in using a 45-minute offset, chosen to differentiate itself from neighboring India (UTC+5:30), which adopted the half-hour offset to keep a single time zone across its vast east-west span. Iran (UTC+3:30) similarly uses a 30-minute offset, with IRDT (UTC+4:30) observed in summer.
Real-World Conversion Examples
These examples use standard (non-DST) offsets. During summer months, times in cities that observe daylight saving will shift by one hour.
8:00 am New York (EST, UTC−5)
= 1:00 pm London (GMT, UTC+0) = 9:00 pm Singapore (SGT, UTC+8)
12:00 pm London (GMT, UTC+0)
= 7:00 am New York (EST, UTC−5) = 9:00 pm Tokyo (JST, UTC+9)
9:00 am Sydney (AEST, UTC+10)
= 11:00 pm (prev. day) London = 6:00 pm (prev. day) New York
5:00 pm Los Angeles (PST, UTC−8)
= 8:00 pm New York (EST) = 1:00 am (next day) London
Frequently Asked Questions
Does the converter account for daylight saving time?
Yes. The converter uses the IANA time zone database, which contains the full historical and future DST rules for every supported zone. When you convert a time, it applies the correct offset for that specific moment - Including whether DST is in effect - Rather than using a fixed offset.
What is the International Date Line?
The International Date Line (IDL) is an imaginary line that runs roughly along the 180-degree meridian in the Pacific Ocean. When you cross it heading west, you gain a full calendar day; crossing it eastward, you go back a day. The line is not straight - It bends around Russia, Kiribati, and several Pacific island nations to keep their territories on a single calendar date.
Why do some countries have half-hour or quarter-hour offsets?
Standard time zones are 15 degrees of longitude wide, each representing one hour. Countries that fall near the boundary of two zones sometimes choose a 30- or 45-minute offset as a compromise. India (UTC+5:30), Iran (UTC+3:30), Afghanistan (UTC+4:30), and Nepal (UTC+5:45) are the most notable examples.
How do I convert time for a future date?
The converter above works for any time you enter, but it applies today's DST status. For a future date - Especially one that crosses a DST boundary - You may need to manually check whether DST will be in effect on that date. In the northern hemisphere, clocks typically spring forward in March–April and fall back in October–November; the exact dates vary by country. Need to find an overlap across multiple cities? Use the Meeting Planner to see business-hour windows across any combination of cities at once.