Time conversion settings
Recent conversion history
| Source | Result | Mode | Offset | Action |
|---|---|---|---|---|
| No saved conversions yet. | ||||
Formula used
PST = UTC − 8 hours PDT = UTC − 7 hours UTC = PST + 8 hours UTC = PDT + 7 hours
Automatic mode uses the America/Los_Angeles timezone rules. Fixed modes always use their stated UTC offsets. Date boundaries are handled before the result appears correctly.
How to use this calculator
- Select the required conversion direction.
- Enter the source date and time.
- Choose automatic, PST, or PDT mode.
- Set your display and adjustment options.
- Press Convert time and review the results.
Use automatic mode for real Pacific locations. Use fixed modes for offset-only calculations. Review transition warnings whenever clocks change seasonally nearby.
UTC, PST, PDT, and Pacific Time
UTC is the global reference for civil time. PST remains eight hours behind UTC year-round. PDT remains seven hours behind UTC year-round.
Pacific Time usually switches between PST and PDT. Automatic mode checks the chosen calendar date. This prevents many seasonal scheduling errors for users.
Example conversions
| UTC time | PST result | PDT result | Notes |
|---|---|---|---|
| 2026-01-15 12:00 | 2026-01-15 04:00 | 2026-01-15 05:00 | Winter dates usually use PST automatically. |
| 2026-07-15 12:00 | 2026-07-15 04:00 | 2026-07-15 05:00 | Summer dates usually use PDT automatically. |
| 2026-07-15 03:00 | 2026-07-14 19:00 | 2026-07-14 20:00 | The Pacific result uses the previous date. |
Frequently asked questions
What is the difference between PST and Pacific Time?
PST is a fixed UTC minus eight offset. Pacific Time may switch seasonally to PDT. Automatic mode follows official Los Angeles timezone transitions.
Does PST observe daylight saving time?
PST itself does not change its fixed offset. Pacific regions may switch from PST to PDT. Choose automatic mode for seasonal local-time calculations.
When should I force PST?
Force PST when you need UTC minus eight. This ignores daylight saving rules for every date. It suits fixed-offset records and technical comparisons.
When should I force PDT?
Force PDT when you need UTC minus seven. This ignores winter changes in Pacific locations. It suits fixed summer-offset calculations and records.
Can this calculator cross midnight?
Yes, date changes are calculated automatically during conversion. Month and year boundaries are also supported. The result labels previous or next dates clearly.
Can I convert Pacific Time back to UTC?
Yes, choose Pacific Time to UTC first. Then select automatic, PST, or PDT mode. The result shows UTC with its exact timestamp.
How are ambiguous DST times handled?
Automatic mode uses PHP timezone transition data. Transition warnings appear near skipped or repeated hours. Confirm critical appointments with every participant directly.
What does the Unix timestamp show?
The timestamp counts seconds since the Unix epoch. It identifies the same instant across all zones. Developers often use it for reliable storage.
Can I convert multiple times together?
Yes, enter one timestamp on each textarea line. The calculator converts up to one hundred entries. Download the generated table as CSV afterward.
Are seconds supported?
Yes, the input accepts optional seconds precisely. Enable result seconds using the provided checkbox. This helps with logs and technical scheduling.
Can I save the results?
You can copy, print, share, or export results. CSV and PDF controls appear after conversion. Browser history stores recent conversions on your device.
Accuracy and limitations
This tool uses installed PHP timezone information. Hosting environments may contain outdated timezone rule packages. Update server timezone data for critical scheduling.