# UTC to PST time converter

Converts a time in UTC (Coordinated Universal Time) to Los Angeles (US Pacific), with the abbreviations and UTC offsets in force on the date and when the difference next changes.

- Page: https://www.acalculator.org/days/utc-to-pst
- JSON spec: https://www.acalculator.org/days/utc-to-pst.json
- Version: 83f9c090d765

## Default answer

Example with the default inputs (Time 17:00, From UTC (Coordinated Universal Time), To Los Angeles (US Pacific), Date September 30, 2026) on the example date Wednesday, September 30, 2026: 5:00 PM on September 30, 2026 in UTC (Coordinated Universal Time) is 10:00 AM on Wednesday, September 30, 2026 in Los Angeles (US Pacific).

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| at | Time | The clock time in the From zone. |
| from | From | The time zone of that time (IANA name). |
| to | To | The time zone to convert to (IANA name). |
| on | Date | The date in the From zone. Today, unless you change it. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| time | Time there | The clock time in the To zone at that moment. |
| date | Date there | The date in the To zone at that moment. |
| difference | The To zone is | How far the To zone’s clock is ahead of or behind the From zone’s clock at that moment. |
| fromZone | From zone | The From zone’s name, abbreviation, and UTC offset at that moment. |
| toZone | To zone | The To zone’s name, abbreviation, and UTC offset at that moment. |
| next | Difference changes next | The next difference and when it starts, in the From zone's local time, within 366 days. |

## Method

Find the instant (UTC) at which the From zone’s clocks show the date and time, then read the To zone’s clock at that instant; both offsets come from the browser’s IANA time zone data.

## Assumptions

- By default this page converts UTC (Coordinated Universal Time) to Los Angeles (US Pacific): the IANA tzdata zones UTC and America/Los_Angeles; the browser supplies their offsets and daylight saving rules (checked against tzdata 2026a), so a rule change arrives with a browser update.
- A time that does not exist in the From zone (skipped when clocks spring forward) has no answer. A time that occurs twice (when clocks fall back) shows both results, earlier first, for every output that differs.
- The difference is the To zone’s UTC offset minus the From zone’s, as “3 hours ahead”, “9 hours 30 minutes behind”, or “the same time”.
- “Difference changes next” is the first moment after the typed time, within 366 days, at which the difference changes: the new difference, then that moment as the From zone’s local date and time (“2 hours ahead from Saturday, October 31, 2026, 11:00 PM”).
- Each zone shows its name and abbreviation from the browser’s Unicode CLDR English names (left out when CLDR has none), then its offset as UTC+hh:mm or UTC−hh:mm.
- Dates from 2000 to 2040 work.

## Worked examples

1. at = 17:00, from = UTC, to = America/Los_Angeles, on = 2026-07-01 gives time = 10:00, date = 2026-07-01, difference = 7 hours behind, fromZone = Coordinated Universal Time (UTC), UTC+00:00, toZone = Pacific Daylight Time (PDT), UTC−07:00, next = 8 hours behind from Sunday, November 1, 2026, 9:00 AM. Source: IANA Time Zone Database, tzdata 2026a (https://www.iana.org/time-zones).
2. at = 17:00, from = UTC, to = America/Los_Angeles, on = 2026-12-01 gives time = 09:00, date = 2026-12-01, difference = 8 hours behind, fromZone = Coordinated Universal Time (UTC), UTC+00:00, toZone = Pacific Standard Time (PST), UTC−08:00, next = 7 hours behind from Sunday, March 14, 2027, 10:00 AM. Source: IANA Time Zone Database, tzdata 2026a (https://www.iana.org/time-zones).

## FAQ

### Is PST 8 hours behind UTC?

PST is: UTC−08:00. From March to November Pacific time is on PDT, UTC−07:00, 7 hours behind UTC. The converter shows whichever Los Angeles uses on the date.

### What is 12:00 UTC in Pacific time?

4:00 AM PST in winter and 5:00 AM PDT in summer.

### Is UTC the same as GMT?

As a clock time, yes: both are UTC+00:00. GMT is also the name of the UK’s winter time; in summer the UK uses BST, UTC+01:00.

### When does the time difference change next?

As of Wednesday, September 30, 2026, Los Angeles is 7 hours behind UTC; it is 8 hours behind from Sunday, November 1, 2026, 9:00 AM UTC time.

## Sources

- 15 U.S.C. 260a, advancement of time (https://www.law.cornell.edu/uscode/text/15/260a)
- IANA Time Zone Database, tzdata 2026a (https://www.iana.org/time-zones)