Compare MST vs BST
See the current time difference between MST and BST, how daylight saving affects the offset, and the best hours to schedule meetings.
How to Find the Time Difference Between MST and BST
Open the MST to BST comparison page: Go to https://www.xconvert.com/time-converter/mst-vs-bst to load a visual comparison between Mountain Standard Time (MST, UTC-7) and British Summer Time (BST, UTC+1). This page is useful when you need to schedule a call between places such as Phoenix and London, especially for remote software teams, customer support coverage, or travel planning between the US Southwest and the UK.
Add relevant cities with the “+ Add City” button: Click “+ Add City” and search for cities that commonly work with MST or BST, such as Phoenix, Denver, London, or Manchester. This helps if you are coordinating with UK finance teams, US-based SaaS operations, or airline itineraries that connect through hubs like London Heathrow while your team works from Arizona or other Mountain Time locations.
Use the grid to drag and compare working hours: Click “Select” to enter selection mode, then drag across the colored timeline on the MST row to highlight a time block, such as 9:00 AM to 11:00 AM MST. That selection converts to 5:00 PM to 7:00 PM BST, which shows that a late-morning meeting in MST lands at the end of the UK workday—useful for deciding whether a product review, legal call, or sales handoff is practical.
Export the selected time for your team or clients: After selecting a range, use the export options shown on the page: ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link. For example, if you confirm a cross-border meeting between an Arizona operations team and a London client success team, exporting the slot ensures everyone receives the appointment in their own local time without manual conversion mistakes.
MST vs BST Offset Explained
MST is 8 hours behind BST. Mountain Standard Time is UTC-7, while British Summer Time is UTC+1, so the exact difference is 8 hours. When it is 9:00 AM in MST, it is 5:00 PM in BST on the same calendar day.
This comparison matters because MST is a standard-time zone, while BST is itself a daylight saving time zone used in the United Kingdom during summer. BST begins when the UK moves clocks forward on the last Sunday in March and ends on the last Sunday in October, when the UK returns to Greenwich Mean Time (GMT, UTC+0). During the BST period, the UK is 8 hours ahead of MST; outside that period, if you compare MST to GMT instead of BST, the difference becomes 7 hours.
A practical complication is that many North American locations do not stay on MST all year. Phoenix, Arizona uses MST year-round and does not observe daylight saving time, making it one of the clearest real-world examples of MST. By contrast, cities such as Denver, Colorado switch between MST (winter) and MDT, UTC-6 (summer), so if you are actually scheduling with Denver in July, you are not comparing MST to BST anymore—you are comparing MDT to BST, which is a 7-hour difference instead of 8.
The seasonal overlap creates short periods in spring and autumn when UK and North American clock changes do not happen on the same date. The UK changes on the last Sunday in March and last Sunday in October, while most US and Canadian DST transitions occur on the second Sunday in March and first Sunday in November. That means if you are coordinating meetings for multinational teams, especially in software, consulting, aviation, or financial services, you should verify the exact date on the grid rather than assuming the offset stays constant throughout March, October, or early November.
For business scheduling, the 8-hour gap usually means there is only a narrow overlap in standard office hours. A 8:00 AM to 10:00 AM MST block corresponds to 4:00 PM to 6:00 PM BST, which can work for same-day meetings with UK partners. However, 1:00 PM MST becomes 9:00 PM BST, so afternoon meetings in MST are generally too late for normal UK office hours unless the British side is working extended support, media, or trading-adjacent shifts.
Frequently Asked Questions
What is the exact time difference between MST and BST?
MST is 8 hours behind BST. Since MST is UTC-7 and BST is UTC+1, adding 8 hours to MST gives the BST time. For example, 7:00 AM MST = 3:00 PM BST, and 12:00 PM MST = 8:00 PM BST.
Is BST always 8 hours ahead of MST?
BST is 8 hours ahead of MST when the UK is observing British Summer Time. BST is not used year-round; it normally runs from the last Sunday in March to the last Sunday in October. When the UK returns to GMT, the difference between MST and UK time becomes 7 hours, not 8.
Does Arizona use MST when comparing with BST?
Yes, most of Arizona, including Phoenix, stays on MST (UTC-7) all year and does not observe daylight saving time. That makes Arizona one of the most reliable real-world references for MST when comparing with BST. If it is 9:00 AM in Phoenix, it is 5:00 PM in London during BST.
Why does the MST to BST difference sometimes seem inconsistent?
The confusion usually happens because people mix MST with Mountain Time generally. True MST is UTC-7, but many Mountain Time cities, including Denver, Salt Lake City, and Calgary, switch to daylight time in warmer months, becoming MDT (UTC-6). If you compare those cities to BST in summer, the gap is 7 hours, so users often think the MST-BST difference changed when in fact the location changed from standard time to daylight time.
What is the best meeting window between MST and BST for work calls?
A practical overlap is usually 8:00 AM to 10:00 AM MST, which converts to 4:00 PM to 6:00 PM BST. This window works well for project standups, agency-client reviews, and legal or procurement calls that need both sides during business hours. Earlier MST times can be better for the UK, but they may be too early for teams in Arizona or other MST locations.
How do I use the xConvert grid to compare MST and BST on a specific date?
Open the page and use the date picker row at the top to choose the exact day, especially around late March, late October, or early November when daylight saving transitions can affect related time zones. Then click “Select” and drag across the MST row to highlight a meeting window; the BST row updates visually so you can see whether the slot falls in UK working hours, evening, or night. This is especially useful for planning interviews, support coverage, or travel-day coordination without manually calculating offsets.
Is London always in BST?
No. London uses BST only during the daylight saving period, typically from the last Sunday in March until the last Sunday in October. Outside that range, London uses GMT (UTC+0), so if you are scheduling winter meetings with a UK office, you should compare MST to GMT rather than MST to BST.
What industries commonly need MST to BST conversion?
This time conversion is common in software development, customer support, digital marketing, consulting, aviation, and e-commerce. UK companies often work with teams or vendors in the US Mountain region, while Arizona-based firms may support British clients in the afternoon UK window. It is also relevant for flight planning and international travel, particularly for itineraries involving Phoenix Sky Harbor and London Heathrow or other UK gateways.