IST to MST

IST is ahead of MST by 11.5 hours today

On 28 August 2026, India Standard Time is on IST at UTC+05:30 and Mountain Standard Time is on MDT at UTC-06:00. The gap between them is 11.5 hours, with MST behind. So 9:00 am in IST is 9:00 pm in MST, and 5:00 pm in IST is 5:00 am in MST. Going the other way, see MST to IST.

The gap is not constant, and that is the part that catches people out

Mountain Standard Time is currently observing daylight saving and changes next on 1 November 2026. India Standard Time does not observe daylight saving, so the gap moves only when Mountain Standard Time changes its clocks — twice a year, by one hour.

When you can actually both be at work

Taking a working day as 9:00 am to 5:00 pm local at each end, there are 0 overlapping hours in a normal day. There is none: the two working days do not touch at all, so any live meeting between India Standard Time and Mountain Standard Time has to sit outside somebody's normal hours. The table above shows which end has the shorter stretch to give up.

Zone rules are set by legislation and change, sometimes at short notice. This page is built against tzdata 2026a, last reviewed 2026-08-18. Quarterly. Zone rules change by legislation, sometimes at short notice. Version and review date are shown on every zone page. The converter above reads your browser's own copy of the zone database, so if a rule has changed since this page was built the live answer follows the new rule — and so does everything above, which is worked out from the same database when you open the page.

Every convention used above — whether the start date counts, how month ends are clamped, which holidays close an office — is written out on the methodology page, including the daylight-saving rules behind the 11.5-hour gap above.