Time zones can be confusing, but understanding the basics makes global scheduling much simpler — whether you are booking a call with a client in Tokyo or figuring out when a live stream starts in your city.
What is UTC?
UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. It is based on atomic clocks and does not change with seasons. Think of it as the "zero line" for all time on Earth.
UTC Offsets
Every time zone is defined by how many hours it is ahead of or behind UTC:
Daylight Saving Time (DST)
Many countries shift their clocks forward by one hour in spring and back in autumn. This changes their UTC offset seasonally and is a common source of scheduling errors. Countries near the equator generally do not observe DST, while the USA, most of Europe, and Australia do.
Key DST dates vary by country and year — never assume DST starts and ends on the same date everywhere.
How to Schedule Across Time Zones Without Errors
Using ZaynClock's World Clock
ZaynClock's World Clock lets you add any city and see its current time in real time, correctly accounting for DST. You can view multiple cities at once, making it easy to find the overlap window that works for everyone on your team.