Which zone this page means. MST is standard time only; MDT (UTC-6) applies from March to November. Arizona stays on MST all year. IST means India Standard Time (UTC+5:30), Irish Standard Time (UTC+1) and Israel Standard Time (UTC+2). This page means the Indian zone, which is one of the few on a half-hour offset.
MST is behind IST by 11.5 hours today
On 19 August 2026, Mountain Standard Time is on MDT at UTC-06:00 and India Standard Time is on IST at UTC+05:30. The gap between them is 11.5 hours, with IST ahead. So 9:00 am in MST is 8:00 pm in IST, and 5:00 pm in MST is 4:00 am in IST. Going the other way, see IST to MST.
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, when clocks go back an hour. India Standard Time does not observe daylight saving at all, so the whole of the seasonal change comes from the MST side: the gap moves by an hour twice a year even though nothing changes in India Standard Time.
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 Mountain Standard Time and India 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.
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.