In the graph below you see the time zone difference between Mountain Daylight Time and India Standard Time. Drag the bubble to adjust the time and to see the corresponding time in the other time zone.
Mountain Daylight Time is the time zone of the US and Canadian states around the Rocky Mountains, including cities like Edmonton, Calgary, Denver and Salt Lake City. India Standard Time is the time zone of India, with places like New Delhi, Mumbai, Bangalore, Kolkata and Colombo.
Usually it is preferable to schedule meetings in the early morning, or late evening for the person in MDT and in the evening, or early morning for the person in IST.
MDT is observed in the Western part of central US and Canada, as well as the North West corner of Mexico. It is 6 hours behind UTC and turns into MST in the summer. In Mexico, this time zone is known as Zona Pacifico (Pacific Zone). The name Mountain Daylight Time comes from it covering the Rocky Mountains in Western United States.
In the US, Arizona, Colorado, Montana, Utah, New Mexico and Wyoming are all observing Mountain Daylight Time but there is also a bunch where part of the state observe MDT and part another time zone, like CDT or PDT.
MDT is observed in parts of Canada, the US and Mexico. The only province in Canada to be fully covered by MDT is Alberta whereas other provinces like British Columbia and Northwest Territories are split between MDT and PDT.
In Mexico, it is only the states in the north western corner of the country, including Baja California, Sinaloa and Chihuahua that observe MDT.
The largest city observing Mountain Daylight Time is Phoenix, followed by Denver and El Paso/Juarez.
MDT is observed in almost all locations that observe Mountain Time, except the states of Arizona (US) and Sinaloa (Mexico). DST is in effect between March and November and adds one hour time difference to UTC.
India, Sri Lanka
Delhi, Colombo, Kolkata and Mumbai
This timezone does not observe daylight saving time so the time difference always stay the same. You however need to pay attention to if the other time zone is observing DST as this will make a difference.
IST can also refer to Irish Standard Time or Israeli Standard time, but most of the times it is India that is being referred to – just make sure to double check this before you send that calendar invite!