Does it account for Daylight Saving Time?

Yes, our converter uses the IANA timezone database, which includes all current DST rules for every timezone in the world.

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All timezones are defined as offsets from UTC.

Can I compare multiple timezones at once?

Yes, you can add multiple cities or timezones and see the equivalent times side by side.

How many timezones are there in the world?

There are 38 distinct UTC offsets in use, ranging from UTC-12 to UTC+14. This includes half-hour (UTC+5:30 India, UTC+9:30 Australia) and 45-minute offsets (UTC+5:45 Nepal, UTC+8:45 Australia).

What is the International Date Line?

The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. When you cross it westward, you gain a day; crossing eastward, you lose a day.

Why do some timezones have 30 or 45 minute offsets?

Countries chose offsets that best matched their solar noon. India uses UTC+5:30 and Nepal uses UTC+5:45 because standard hourly offsets didn't align well with their geography.

Which country has the most timezones?

France has the most (12 timezones) due to overseas territories. Russia spans 11 timezones. The US has 6 (including Hawaii and Alaska).

BST to MDT

-7h

BST

BSTSOURCE

UTC+01:00☀ DST active

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

MDT

UTC-06:00☀ DST active

HH05

MM00

05:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

BST

MDT

12:00 AM

5:00 PM-1

2:00 AM

7:00 PM-1

4:00 AM

9:00 PM-1

6:00 AM

11:00 PM-1

8:00 AM

1:00 AM

10:00 AM

3:00 AM

12:00 PM

5:00 AM

2:00 PM

7:00 AM

4:00 PM

9:00 AM

6:00 PM

11:00 AM

8:00 PM

1:00 PM

10:00 PM

3:00 PM

Green rows indicate typical business hours (9 AM - 5 PM)

BST and MDT on the World Map

The map below highlights the BST (British Summer Time) and MDT (Mountain Daylight Time) timezone regions across the globe.

BST Zone

→

MDT Zone

Explore all world timezones interactively →

BST – British Summer Time

UTC+01:00

British Summer Time (BST, UTC+01:00) is the daylight saving period in the United Kingdom, running from late March to late October.

Countries in BST

United Kingdom

Major Cities in BST

LondonBirminghamManchesterGlasgowEdinburghCardiffBelfastLiverpoolBristolLeeds

Key Facts about BST

•BST runs from the last Sunday in March to the last Sunday in October.
•BST is exactly one hour ahead of GMT, the UK's standard time.
•During BST, London is 4 hours ahead of New York while the US is on Eastern Daylight Time.
•The Isle of Man and the Channel Islands also observe BST.

Daylight Saving:Yes – switches to BST

Learn more about BST on Wikipedia

MDT – Mountain Daylight Time

UTC-06:00

Mountain Daylight Time (MDT) is the daylight saving offset in the Mountain Time Zone, 6 hours behind UTC.

Countries in MDT

United States (Mountain)Canada (Alberta)

Major Cities in MDT

DenverCalgaryEdmontonSalt Lake CityBoise

Key Facts about MDT

•MDT shares the same offset as CST (UTC-06:00).
•Arizona does not switch to MDT, remaining on MST.

Daylight Saving:Yes – switches to MST

Learn more about MDT on Wikipedia

Understanding the -7h Gap: BST vs MDT

BST runs on British Summer Time (BST) at UTC+01:00. MDT runs on Mountain Daylight Time (MDT) at UTC-06:00. That puts BST 7 hours behind MDT — a difference of -7h at the current offsets.

In practice, when it is 9:00 AM in BST it is 2:00 AM in MDT. Midnight in BST is 5:00 PM in MDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.

BST to MDT time conversion table

BST (BST)	MDT (MDT)	Day
12:00 AM	5:00 PM	previous day
6:00 AM	11:00 PM	previous day
7:00 AM	12:00 AM	same day
8:00 AM	1:00 AM	same day
9:00 AM	2:00 AM	same day
12:00 PM	5:00 AM	same day
3:00 PM	8:00 AM	same day
5:00 PM	10:00 AM	same day
6:00 PM	11:00 AM	same day
9:00 PM	2:00 PM	same day

Why people convert BST to MDT time

Scheduling a call from BST to MDT: a 10:00 AM start in BST lands at 3:00 AM in MDT, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both BST and MDT are inside the 9-to-5 working day between 4:00 PM and 5:00 PM BST time (9:00 AM–10:00 AM MDT). That is roughly 1 hours of usable overlap.
Watching a live event or market open: BST viewers need 2:00 AM in MDT to catch a 9:00 AM start there, and 7:00 AM if the event is anchored to BST.

Always state the zone abbreviation, not just the hour. "3:00 PM BST" is unambiguous; "3 PM" across a -7h gap is not.
Block 4:00 PM–5:00 PM BST as the recurring meeting window if you work primarily from BST and need MDT colleagues present.

About BST (British Summer Time)

British Summer Time (BST) is the daylight saving period in the United Kingdom, when clocks move one hour forward from Greenwich Mean Time (GMT, UTC+00:00) to UTC+01:00. It runs from the last Sunday in March to the last Sunday in October. England, Scotland, Wales and Northern Ireland all follow it, along with the Isle of Man and the Channel Islands of Jersey and Guernsey. During BST, London is one hour ahead of UTC, four hours ahead of New York on Eastern Daylight Time, and five hours ahead of New York once the United States returns to Eastern Standard Time in November. BST is also used to abbreviate Bangladesh Standard Time (UTC+06:00), which is listed separately on this site.

About MDT (Mountain Daylight Time)

Mountain Daylight Time (MDT) is observed during summer months in the Mountain Time Zone, except in Arizona which stays on MST year-round. MDT aligns with Central Standard Time (CST) at UTC-06:00.

Best time to call between BST and MDT

Both BST and MDT sit inside the 9 AM – 5 PM working day between 4:00 PM–5:00 PM BST, which is 9:00 AM–10:00 AM MDT. That gives roughly 1 hours of shared time — the safest window for a live call or meeting.

Business hours overlap

BST and MDT overlap for only 60 minutes (4:00 PM–5:00 PM BST), so meetings have to be booked precisely.

BST is 7 hours behind MDT (BST UTC+01:00 → MDT UTC-06:00). The shared working window is 4:00 PM–5:00 PM BST. Remember to re-check around daylight-saving transitions.