MDT — Mountain Daylight Time
See what MDT means, where it is used, how it relates to MST, and convert Mountain Daylight Time to other time zones.
Countries: Canada, Mexico, United States
How to Convert MDT to Other Time Zones
Open the MDT converter page: Go to https://www.xconvert.com/time-converter/mdt-time-zone to load a visual comparison grid with Mountain Daylight Time (MDT) already shown as the reference row. This page is useful when you need to line up working hours in places such as Boise, Idaho or Chihuahua, Mexico with teams in other regions, for example scheduling a software deployment, a sales call, or a travel handoff across North America.
Add comparison cities: Click “+ Add City” and search for cities that commonly interact with MDT locations, such as New York for finance and media, Los Angeles for logistics and West Coast operations, or Mexico City for domestic coordination within Mexico. Adding these rows lets you compare MDT against major business hubs where companies often need to coordinate customer support coverage, supply-chain timing, or remote team meetings.
Select a time range on the grid: Click “Select” to enter selection mode, then drag across the MDT row to highlight a block such as 9:00 AM to 11:00 AM MDT. That same range converts to 11:00 AM to 1:00 PM EDT in New York and 8:00 AM to 10:00 AM PDT in Los Angeles, which helps confirm whether a morning meeting in Boise still lands inside standard office hours for East Coast stakeholders and West Coast partners.
Export or share the selected time: After selecting the range, use the export options that appear — ICS download, Google Calendar, Gmail, Copy to clipboard, or Share link — to send the chosen slot to clients, recruiters, distributed engineering teams, or travel coordinators. For example, an ICS file ensures everyone sees the meeting in their own local time automatically, while a Share link is useful for quickly confirming a cross-border call between Idaho, Texas, and Chihuahua without repeated manual conversions.
About Mountain Daylight Time (MDT)
Mountain Daylight Time (MDT) is the daylight saving time variant of the Mountain Time Zone, and it has an exact offset of UTC−06:00. That means MDT is 6 hours behind Coordinated Universal Time, so when it is 12:00 PM UTC, it is 6:00 AM MDT. In practical scheduling terms, MDT is 1 hour behind Eastern Daylight Time (EDT) and 1 hour ahead of Pacific Daylight Time (PDT), so 9:00 AM MDT equals 10:00 AM EDT and 8:00 AM PDT.
MDT is used seasonally in parts of the United States, Canada, and Mexico during the daylight saving portion of the year. In the United States, MDT applies in areas that observe Mountain Time with summer clock changes, including cities such as Boise, Meridian, Nampa, Idaho Falls, and Pocatello in Idaho. In Mexico, MDT is used in parts of the north including Chihuahua, Ciudad Delicias, Cuauhtémoc, Parral, and Nuevo Casas Grandes, where cross-border trade, trucking, manufacturing, and regional government scheduling often depend on accurate time alignment.
The counterpart to MDT is Mountain Standard Time (MST), which uses the offset UTC−07:00. When daylight saving time is not in effect, clocks move back from MDT to MST, making local time one hour earlier by the clock than it was during summer. This distinction matters for airline itineraries, warehouse cutoffs, customer support shifts, and interview scheduling because a meeting set for 2:00 PM MDT in July would correspond to 2:00 PM MST only after the seasonal switch has occurred.
MDT can share the same UTC−06:00 offset as other abbreviations such as CST, CT, EAST, GALT, MT, and S, but those abbreviations are not automatically interchangeable. The same numeric offset does not guarantee the same region, daylight saving rule, or legal local time, which is why users should compare by city or region rather than abbreviation alone when arranging international calls or travel.
MDT and Daylight Saving Time
MDT exists only when daylight saving time is active in Mountain Time areas that observe seasonal clock changes. During this period, clocks are advanced 1 hour ahead of MST, changing the region from UTC−07:00 (MST) to UTC−06:00 (MDT). This shift creates longer evening daylight and affects everything from school schedules to airline departure boards and remote team overlap with Europe and the U.S. East Coast.
In the United States, Mountain Time regions that observe daylight saving time switched from MST to MDT on Sunday, March 9, 2025, at 2:00 AM local time, when clocks moved forward to 3:00 AM. They will switch back from MDT to MST on Sunday, November 2, 2025, at 2:00 AM local time, when clocks move back to 1:00 AM. For business users, this means a recurring meeting with New York, Toronto, or London may temporarily shift relative to international partners if those regions change clocks on different dates.
In Canada, Mountain Time areas that observe daylight saving time follow the same 2025 transition dates: March 9, 2025 for the spring forward and November 2, 2025 for the fall back. This is especially relevant for transportation, energy, and public-sector coordination across western Canada and the northern U.S., where one missed offset change can affect dispatch windows or service coverage.
In Mexico, daylight saving observance is more region-specific because national time rules changed in recent years. Border and selected northern areas may still align with U.S. seasonal changes for economic and cross-border reasons, but not every Mexican state follows the same schedule. If you are coordinating with Chihuahua or nearby industrial cities connected to U.S. manufacturing and freight corridors, checking the exact city on the converter grid is more reliable than assuming all Mexican locations switch on the same date.
Frequently Asked Questions
What does MDT stand for?
MDT stands for Mountain Daylight Time. It is the daylight saving version of Mountain Time and uses the offset UTC−06:00, which is one hour ahead of Mountain Standard Time (MST) at UTC−07:00.
Is MDT the same as MST?
No, MDT and MST are not the same. MDT is used during the daylight saving period and is UTC−06:00, while MST is used during standard time and is UTC−07:00, so MDT is exactly 1 hour ahead of MST. If it is 3:00 PM MDT, it would be 2:00 PM MST in a place observing standard time.
Which cities use MDT?
Cities that use MDT during the daylight saving season include Boise, Meridian, Nampa, Idaho Falls, and Pocatello in the United States, along with Chihuahua, Ciudad Delicias, Cuauhtémoc, Parral, and Nuevo Casas Grandes in Mexico where applicable under local rules. These cities are important for regional logistics, education, healthcare, agriculture, and cross-border manufacturing, so accurate time conversion is often necessary for meetings and transport planning.
What is the UTC offset for MDT?
The exact UTC offset for MDT is UTC−06:00. This means MDT is 6 hours behind UTC, so when it is 18:00 UTC, it is 12:00 PM MDT. Compared with other U.S. time zones in summer, MDT is typically 1 hour behind EDT, 2 hours behind ADT, and 1 hour ahead of PDT.
When does MDT change?
In U.S. and Canadian regions that observe Mountain Time daylight saving rules, MDT begins on March 9, 2025, and ends on November 2, 2025. At the start, clocks move forward from 2:00 AM to 3:00 AM, and at the end, clocks move back from 2:00 AM to 1:00 AM. In Mexico, the exact change depends on the local jurisdiction, so city-level verification is important.
Is MDT used all year?
No, MDT is not used year-round. It is only used during the daylight saving season; outside that period, the same regions usually revert to MST (UTC−07:00). This matters for recurring meetings, because a standing summer call with Boise may shift by one hour in UTC once the region returns to standard time.
How far behind UTC is Mountain Daylight Time?
Mountain Daylight Time is 6 hours behind UTC, written as UTC−06:00. For example, 9:00 PM UTC converts to 3:00 PM MDT, which is useful when coordinating with global teams that schedule in UTC, such as cloud operations, cybersecurity monitoring, or international customer support.
Why does MDT sometimes match other time zone abbreviations?
MDT can share the same numeric offset as abbreviations like CST, CT, EAST, GALT, MT, and S at certain times of year, but that does not mean they represent the same place or follow the same daylight saving rules. A matching offset only tells you the current hour difference from UTC; for calendar invites, flight planning, and legal deadlines, you should always confirm the specific city or region rather than relying on abbreviation alone.