India - USA Meeting Planner

Coordinating a single meeting across India and the four contiguous US timezones is one of the hardest scheduling puzzles in modern business. India sits at UTC+5:30 with no DST; the US runs from UTC-5 to UTC-8 in winter and UTC-4 to UTC-7 in summer. The Indian working day is 9:30 AM to 7:00 PM IST; the US working day is roughly 9 AM to 5 PM local. The only window where all five zones overlap in business hours is essentially zero - which means follow-the-sun teams have to compromise.

The cleanest compromise is the ‘Indian evening / US morning’ window. Mumbai 7:30 PM IST equals New York 10:00 AM EDT (or 9:00 AM EST), Chicago 9:00 AM CDT (or 8:00 AM CST), Denver 8:00 AM MDT, and San Francisco 7:00 AM PDT. That single slot - 7:30 PM Mumbai - is the most-booked recurring meeting time in the global IT services industry, because everyone is awake and at their desk or close to it.

The IT services industry has built dedicated ‘Eastern shift’ teams in Bengaluru, Hyderabad, Pune, Chennai, Noida, and Gurgaon precisely because the natural overlap is so narrow. These teams work 5:00 PM to 2:00 AM IST so they can attend the full US workday meetings. Companies like Infosys, TCS, Wipro, HCL, Cognizant, Tech Mahindra, Mphasis, and LTIMindtree have rotation rules baked into their HR systems that limit Eastern shifts to roughly 5 days at a time per engineer.

Daylight Saving Time, which the US observes from the second Sunday of March to the first Sunday of November, complicates the math by an hour twice a year. India does not observe DST. So during US DST, IST is 9.5 hours ahead of ET, 10.5 hours ahead of CT, 11.5 hours ahead of MT, and 12.5 hours ahead of PT. During US winter the gaps are all an hour wider. This page uses the IANA Time Zone Database via the Intl.DateTimeFormat API so the math is automatic.

Arizona is a wrinkle in the math. Most of Arizona (except the Navajo Nation) does not observe DST. So while Denver shifts MDT (UTC-6) in summer, Phoenix stays on Mountain Standard (UTC-7) year-round. For India calls from Phoenix specifically, the gap is always 12 hours 30 minutes - the easiest US gap to remember because the IST hand is simply the PT hand inverted by 12.

Video conferencing tools - Zoom, Google Meet, Microsoft Teams, Webex, and Slack Huddles - all default to scheduling in the host's local timezone with auto-conversion in the invite. But the auto-conversion only works if both sides have the correct system timezone set. A surprising fraction of meeting confusion across the India-US bridge comes from one side's laptop having the wrong timezone configured. This page's grid solves that by showing all five zones at once.

The IANA Time Zone Database (TZDB), founded by Arthur David Olson at NIH in 1986 and maintained at iana.org/time-zones, encodes the full DST history for every region. Identifiers like America/Phoenix (which fixes the Arizona quirk), America/Indiana/Indianapolis (which has its own oddities), and Asia/Kolkata (single offset since 1906) make this calculator robust against the typical ‘timezone bug’ class of errors. The grid below uses TZDB-backed conversion for every cell.