What the IST to PST Converter Does
This tool converts a time in Indian Standard Time (IST, used across India and Sri Lanka) into Pacific Standard Time (PST, used in the western United States and Canada, such as California, Washington and British Columbia). You enter a single IST time and the converter instantly returns the equivalent PST time, including a note when the result falls on the previous or next calendar day.
How to Use It
The calculator has one input: IST Time, which you provide as an hour and a minute (24-hour format). Type the hour you want to convert from India time, add the minutes, and the tool does the rest. There are no other settings to worry about — the time-zone offsets are built in.
- Enter the IST hour (0–23).
- Enter the IST minutes (0–59).
- Read off the converted PST hour and minute, plus any day-shift flag.
The Formula Explained
IST is 5 hours and 30 minutes ahead of UTC, and PST is 8 hours behind UTC. The tool works in two steps:
- IST → UTC: subtract 5 hours 30 minutes. If subtracting 30 minutes makes the minutes negative, it adds 60 minutes back and borrows one hour.
- UTC → PST: subtract a further 8 hours. The net difference is therefore 13 hours 30 minutes behind IST.
If the resulting hour drops below 0, the tool adds 24 and flags the result as the previous day; if it goes to 24 or more, it subtracts 24 and flags the next day.
Worked Example
Suppose you enter 10:00 IST. First, IST to UTC: 10:00 − 5:30 = 4:30 UTC. Then UTC to PST: 4:30 − 8:00 = −3:30, so add 24 hours to get 20:30 PST, flagged as the previous day. So a 10 AM meeting in India lands at 8:30 PM the day before on the US Pacific coast.
FAQ
Does this account for Daylight Saving Time? No. The tool uses a fixed offset of 13 hours 30 minutes (PST, standard time). During US daylight months the Pacific zone shifts to PDT (12.5 hours behind IST), so adjust by one hour in summer.
Why does the result sometimes show a different day? Because PST is so far behind IST, many morning and early-afternoon IST times convert to the previous calendar day in PST. The converter flags this automatically.
What is the exact time difference? IST is 13 hours and 30 minutes ahead of PST.
