How Time Zones Work: Schedule Calls Across Countries

The Earth is divided into time zones so that noon is roughly when the sun is highest. All zones are described as an offset from UTC, Coordinated Universal Time.

Common offsets

• Pakistan (PKT): UTC+5
• United Arab Emirates: UTC+4
• United Kingdom: UTC+0 in winter, UTC+1 in summer

For example, when it is 9:00 AM in Pakistan, it is 8:00 AM in the UAE. In the UK it is 4:00 AM in winter and 5:00 AM in summer.

Daylight saving time

Many countries move clocks forward in summer and back in winter, and the dates differ between regions. Pakistan generally does not use daylight saving, so the gap with the UK and the USA changes during the year.

Scheduling tips

1. Always write the time zone, such as 3:00 PM PKT.
2. Check for daylight saving changes around March and October to November.
3. Choose a time that is reasonable for everyone, not just for you.
4. Use UTC in shared documents to avoid confusion.

A meeting example

Imagine a team in Karachi (UTC+5) and London in summer (UTC+1). The gap is four hours, so 3:00 PM in Karachi is 11:00 AM in London. With New York, Pakistan is 10 hours ahead in winter and 9 hours ahead in summer, so 9:00 AM in Pakistan is 11:00 PM the previous day in New York in winter.

Common mistakes

• Forgetting that the date can change, not only the hour.
• Assuming all countries change clocks on the same day. The USA and Europe use different dates.
• Writing a time without naming the time zone.

Frequently asked questions

What is the difference between GMT and UTC?

For everyday use they are the same. UTC is the modern standard that clocks are based on.

Are all offsets whole hours?

No. India uses UTC+5:30 and Nepal uses UTC+5:45, so always check the exact offset.

Compare cities with our Time Zone Converter or watch live times on the World Clock.