Last updated: March 2026
How to Convert Time Zones
Converting between time zones is one of the most common challenges in our globally connected world. Whether you are scheduling a call with a client overseas, catching a live event broadcast from another continent, or coordinating with a distributed team, getting the time right is critical. A single hour mistake can mean a missed meeting or a wasted day.
The basic principle is straightforward: every time zone is defined as an offset from UTC (Coordinated Universal Time). To convert between two zones, you find the difference in their UTC offsets and add or subtract accordingly. For example, New York (UTC-5) to London (UTC+0) is a 5-hour difference — so 2 PM in New York is 7 PM in London. But this simple math gets complicated quickly when daylight saving time enters the picture.
Daylight saving time shifts the offset by one hour during summer months in participating countries. The US shifts clocks forward on the second Sunday of March; the EU changes on the last Sunday of March. During the weeks when one country has shifted but the other hasn't, the usual time difference changes. New York to London is normally 5 hours, but for a few weeks in March it becomes 4 hours because the US springs forward before the UK does.
Things get even trickier with half-hour and quarter-hour offsets. India (UTC+5:30) means that converting from New York to Mumbai isn't just adding hours — it's adding 10 hours and 30 minutes during EST, or 9 hours and 30 minutes during EDT. Nepal (UTC+5:45) and the Chatham Islands (UTC+12:45) add similar complexity. This is why a reliable converter is far more practical than mental math.
Pro tip: when scheduling across many time zones, use the Meeting Planner tab to visualize work-hour overlaps. It shows you at a glance which hours work for everyone, eliminating the tedious back-and-forth of proposing times that only work for some participants.
Frequently Asked Questions
How do I convert time between two time zones?
Select the source time zone and enter the time you want to convert. Then add one or more target time zones. The converter instantly shows the equivalent time in each target zone, including whether it falls on the same day or the next/previous day. All conversions account for the current daylight saving time rules.
Does this converter handle daylight saving time?
Yes. The converter uses the JavaScript Intl API, which references the IANA timezone database — the same database used by operating systems and smartphones worldwide. When you convert a time, the tool automatically applies the correct DST offset for that specific date. For example, converting 3 PM EST on July 15 will correctly use EDT (UTC-4) rather than EST (UTC-5).
Why does the converted time show a different date?
When you convert time across enough time zones, the result may land on a different calendar date. For example, 11 PM in New York on Monday is 1 PM on Tuesday in Tokyo (UTC+9). The converter flags this with a 'Different day' badge so you never accidentally schedule something on the wrong date.
Can I convert to multiple time zones at once?
Yes. You can add as many target time zones as you need. This is especially useful when coordinating with teams across multiple cities — you can see the converted time for London, Mumbai, Tokyo, and Sydney all in one view, making it easy to find a time that works for everyone.
What is the International Date Line?
The International Date Line (IDL) is an imaginary line running through the Pacific Ocean, roughly following the 180th meridian. When you cross it heading west, you advance one calendar day; heading east, you go back one day. This is why it's possible for it to be Tuesday in Auckland while it's still Monday in Honolulu, even though they're relatively close geographically. The converter handles date line crossings automatically.