IST to PST time converter

How far apart are Kolkata and Los Angeles?

It depends on the date. Los Angeles is 12 hours 30 minutes behind Kolkata while Kolkata is on IST and Los Angeles on PDT. Los Angeles is 13 hours 30 minutes behind Kolkata while Kolkata is on IST and Los Angeles on PST. The exact dates for 2026 and 2027 are below, worked out from the same time zone database your browser uses — not remembered.

2026

2027

IST to PST hour table

Every hour of a Kolkata day, read across to Los Angeles — one column per gap, so pick the column for today's date from the table above. A row marked +1 day is already tomorrow there; −1 day is still yesterday.

Each column is one value of the gap; the clock names under it are the ones in force when that gap applies. For a half-hour time or a third city, use the timeline above: every clock moves to the instant you pick.

Working across Kolkata and Los Angeles

India to the US West Coast is close to the largest time difference two working populations regularly deal with: thirteen and a half hours while Los Angeles, San Francisco and Seattle are on Pacific Standard Time, twelve and a half while they are on Pacific Daylight Time. Half a day plus a half hour, in other words. Whatever the time is in Bengaluru, it is almost exactly the opposite end of the clock in California, and the calendar date is usually different too — India's Tuesday morning is California's Monday evening.

The half-day gap has a practical consequence that a smaller difference does not: there is no shared working hour at all. When a Pune engineer starts at 9am, it is 7:30pm the previous evening in San Francisco during PST and 8:30pm during PDT; when a Bay Area engineer starts at 9am, it is 10:30pm or 9:30pm in India. Every synchronous conversation between the two coasts of this pair costs one side its evening, and the honest way to plan it is to decide in advance whose evening, and rotate. The daylight bands on the timeline above make the cost visible: drag to any candidate hour and one of the two bands will be dark.

The gap moves on the American side only. India has had no daylight saving since the 1940s and keeps UTC+5:30 the whole year; the United States advances its clocks on the second Sunday in March and puts them back on the first Sunday in November, so the difference is twelve and a half hours between those dates and thirteen and a half outside them. The dates printed above are worked out from your browser's own time zone data for this year and next, not remembered. If a standing call feels like it has drifted by an hour, it has — look at whether the invite was fixed in Pacific time or in IST.

PST is a less ambiguous abbreviation than IST, but it has its own trap: people write PST all year when for eight months the West Coast is actually on PDT. A message saying "3pm PST" in July almost certainly means 3pm Pacific time as the sender's clock shows it, which is PDT, UTC−7. The tool above sidesteps the question by working from the IANA zone America/Los_Angeles, which knows which of the two applies on any given day. The abbreviation IST, meanwhile, is also used by Israel and Ireland; on a page like this the context is clear, but in an email it may not be.

Because the two cities are so far apart around the clock, this is the pair where the vertical rule marking local midnight on each band earns its place. A deadline written as "Friday close of business, Pacific" is Saturday morning in India, and a release scheduled for "Monday 00:00 IST" happens on Sunday morning in California. If the time you are holding is a Unix timestamp rather than a wall-clock time, decode it in the epoch converter first — it has no time zone of its own.

Sources

The offsets, dates and hour tables above are computed when this page is built, from the time zone rules your browser itself ships. The rules come from:

• IANA Time Zone Database — the rules every browser ships
• NIST — Daylight Saving Time rules (United States)
• ECMA-402 — the Intl.DateTimeFormat standard these figures are computed with