There is no overlap between 09:00–18:00 working days in these two places.
How many hours is IST ahead of PDT?
As abbreviations, PDT is always 12.5 hours behind of IST: IST is UTC+5:30 and PDT is UTC−7. To convert, subtract 12.5 hours.
When the IST to PDT time difference changes
For most of the year PDT is 12.5 hours behind of IST. From 1 November to 31 December 2026, PDT is 13.5 hours behind of IST instead, because the two places change their clocks on different dates. Meetings booked by the usual gap land an hour off in those weeks.
Dates
PDT vs IST
Length
8 March 2026 to 31 October 2026
12.5 hours behind
238 days
1 November 2026 to 31 December 2026
13.5 hours behind
61 days
1 January 2027 to 13 March 2027
13.5 hours behind
72 days
14 March 2027 to 6 November 2027
12.5 hours behind
238 days
7 November 2027 to 31 December 2027
13.5 hours behind
55 days
Calling hours for IST and PDT
When PDT is 12.5 hours behind of IST: no shared 09:00 to 17:00 hours; try 20:00 in IST (07:30 in PDT).
When PDT is 13.5 hours behind of IST: no shared 09:00 to 17:00 hours; one side has to take the call outside office hours.
Frequently asked questions about IST and PDT time
How many hours ahead is PDT of IST?
PDT (UTC−7) is 12.5 hours behind of IST (UTC+5:30).
Does the time difference between IST and PDT change?
Yes. It is usually 12.5 hours behind, but changes when one side moves its clocks: 13.5 hours behind from 1 November to 31 December 2026; 13.5 hours behind from 1 January to 13 March 2027.