DAYLIGHT TIME PROFILE
Pacific Daylight Time (PDT) Summary
UTC Offset: UTC-7 (7 hours behind GMT)
Active Window: 2nd Sunday March to 1st Sunday November
Standard Counterpart: PST (Pacific Standard Time, UTC-8)
Major Cities: Los Angeles, San Francisco, Seattle, Vancouver
Arizona Alignment: Matches Arizona (MST UTC-7) in summer
Spring Shift: Clocks spring forward 1 hour (2:00 AM → 3:00 AM)
Pacific Daylight Time (PDT) is the daylight saving time offset observed across western North America from March through November. Operating at UTC-7, PDT advances local clocks by one hour relative to winter standard time (PST UTC-8). PDT governs key tech keynotes, streaming media debuts, and West Coast commerce across California, Washington, Oregon, and British Columbia.
1. What is Pacific Daylight Time (PDT)?
Pacific Daylight Time (PDT) is the summer daylight saving phase of the Pacific Time Zone in North America. Governed by the US Uniform Time Act, PDT maintains an offset of UTC-7, placing local time 7 hours behind Coordinated Universal Time (UTC) and Greenwich Mean Time (GMT).
PDT covers major technology and entertainment hubs including Los Angeles, San Francisco, San Jose, Seattle, Portland, Las Vegas, Vancouver, and Tijuana.
Figure 1: Summer Timezone Alignment (California PDT ≡ Arizona MST)
Figure 1: Illustration showing that California during PDT (UTC-7) matches the exact wall-clock time of Arizona (MST UTC-7) during summer months.
2. PDT vs. PST & Summer Alignment with Arizona (MST)
Key operational dynamics of Pacific Daylight Time include:
- PDT vs PST: PDT is UTC-7 (summer), whereas PST is UTC-8 (winter). Moving from PST to PDT advances local clocks by 1 hour.
- PDT vs EDT: During summer, both coasts advance their clocks simultaneously. Thus, PDT (UTC-7) remains 3 hours behind EDT (UTC-4).
- PDT vs Arizona (MST): Arizona does not observe Daylight Saving Time and remains on Mountain Standard Time (MST, UTC-7) year-round. Therefore, during summer, Los Angeles and Phoenix share the exact same clock time.
For a deep dive into global daylight saving rules, see Daylight Saving Time Explained.
3. Daylight Saving Transition Calendar & Rules
Annual transition dates follow US federal rules:
| Transition Event | Date & Time Rule | Clock Adjustment |
|---|---|---|
| Spring Forward (PST → PDT) | 2nd Sunday of March at 2:00 AM | Clocks jump from 2:00 AM to 3:00 AM PDT (+1 hour) |
| Fall Back (PDT → PST) | 1st Sunday of November at 2:00 AM | Clocks fall back from 2:00 AM to 1:00 AM PST (-1 hour) |
4. Geographic Extent & Regional Exceptions
Pacific Daylight Time covers key West Coast jurisdictions:
- United States: California, Washington, Oregon (majority), Nevada. See USA Time Zones.
- Canada: British Columbia (Vancouver, Victoria). See Canada Time Zones.
- Mexico: Baja California (Tijuana, Mexicali) synchronizes with US PDT rules.
5. Global PDT Time Conversion Tables
Convert Pacific Daylight Time (PDT, UTC-7) to major world time zones during summer:
| PDT (UTC-7) | GMT (UTC+0) PDT to GMT | EDT (UTC-4) PDT to EDT | CDT (UTC-5) PDT to CDT | BST (UTC+1) PDT to BST | IST (UTC+5:30) PDT to IST |
|---|---|---|---|---|---|
| 00:00 PDT (Midnight) | 07:00 GMT | 03:00 EDT | 02:00 CDT | 08:00 BST | 12:30 IST |
| 06:00 PDT | 13:00 GMT | 09:00 EDT | 08:00 CDT | 14:00 BST | 18:30 IST |
| 09:00 PDT | 16:00 GMT | 12:00 EDT | 11:00 CDT | 17:00 BST | 21:30 IST |
| 12:00 PDT (Noon) | 19:00 GMT | 15:00 EDT | 14:00 CDT | 20:00 BST | 00:30 IST (Next Day) |
| 15:00 PDT | 22:00 GMT | 18:00 EDT | 17:00 CDT | 23:00 BST | 03:30 IST (Next Day) |
| 18:00 PDT | 01:00 GMT (Next Day) | 21:00 EDT | 20:00 CDT | 02:00 BST (Next Day) | 06:30 IST (Next Day) |
For live, interactive conversion calculation, use our GMT to PDT Converter.
Figure 2: North American Summer Daylight Saving Offsets
Figure 2: Position of PDT (UTC-7) within the North American summer daylight saving continuum.
6. Tech Industry Keynotes, Streaming Debuts & Server Scheduling
Major Apple, Google, and Meta developer keynotes originate live in California at 10:00 AM PDT, creating peak global network traffic across Asia, Europe, and the Americas.
Software engineers operating globally distributed infrastructure ensure background job queues process timestamps in UTC to avoid missing scheduled execution windows during PDT transitions. See our guide on JavaScript Time Zone Handling.
7. Frequently Asked Questions (PDT)
What does PDT stand for?
PDT stands for Pacific Daylight Time. It is the daylight saving time offset (UTC-7) observed along the Pacific coast of North America during the spring, summer, and early autumn months.
What is the UTC offset for PDT?
The UTC offset for Pacific Daylight Time (PDT) is UTC-7. Local time in the PDT zone is exactly 7 hours behind Coordinated Universal Time (UTC) and Greenwich Mean Time (GMT).
Is PDT the same offset as MST?
Yes. Both Pacific Daylight Time (PDT) and Mountain Standard Time (MST) operate on a UTC-7 offset. During summer, when Los Angeles is on PDT (UTC-7) and Phoenix is on MST (UTC-7), California and Arizona share the exact same clock time.
When is PDT active during the year?
PDT is active from the second Sunday of March (when clocks 'spring forward' from 2:00 AM to 3:00 AM) until the first Sunday of November (when clocks 'fall back' from 2:00 AM to 1:00 AM).
Which major cities observe Pacific Daylight Time?
Major metropolitan cities observing PDT during summer include Los Angeles, San Francisco, San Jose, Seattle, San Diego, Portland, Las Vegas, Vancouver, and Tijuana.
What is the difference between PDT and PST?
PDT (Pacific Daylight Time) is UTC-7, observed during summer daylight saving months. PST (Pacific Standard Time) is UTC-8, observed during winter standard time months.
How far behind GMT is PDT?
PDT is 7 hours behind Greenwich Mean Time (GMT/UTC+0). When it is 12:00 PM (noon) GMT in London, it is 5:00 AM PDT in Los Angeles and Seattle.
How do I convert PDT to Eastern Daylight Time (EDT)?
Pacific Daylight Time (PDT, UTC-7) is 3 hours behind Eastern Daylight Time (EDT, UTC-4). To convert PDT to EDT, add 3 hours (e.g., 10:00 AM PDT equals 1:00 PM EDT).
How do I convert PDT to Central Daylight Time (CDT)?
Pacific Daylight Time (PDT, UTC-7) is 2 hours behind Central Daylight Time (CDT, UTC-5). To convert PDT to CDT, add 2 hours (e.g., 1:00 PM PDT equals 3:00 PM CDT).
Why does Arizona match California time during the summer?
Most of Arizona does not observe Daylight Saving Time and remains on Mountain Standard Time (MST, UTC-7) year-round. When California advances to Pacific Daylight Time (PDT, UTC-7) in March, both states align on UTC-7 until November.
What is the time difference between PDT and Central European Summer Time (CEST)?
Central European Summer Time (CEST, UTC+2) is 9 hours ahead of Pacific Daylight Time (PDT, UTC-7). When it is 8:00 AM PDT in Los Angeles, it is 5:00 PM CEST in Berlin and Paris.
What is the time difference between PDT and India Standard Time (IST)?
India Standard Time (IST, UTC+5:30) is 12 hours and 30 minutes ahead of Pacific Daylight Time (PDT, UTC-7). When it is 7:00 AM PDT in Los Angeles, it is 7:30 PM IST in New Delhi.
What is the time difference between PDT and British Summer Time (BST)?
British Summer Time (BST, UTC+1) is 8 hours ahead of Pacific Daylight Time (PDT, UTC-7). When it is 9:00 AM PDT in San Francisco, it is 5:00 PM BST in London.
How do tech keynotes (Apple WWDC, Google I/O) manage PDT scheduling?
Major technology conferences hosted in California schedule morning keynotes at 10:00 AM PDT. This aligns with 1:00 PM EDT (New York) and 6:00 PM BST (London), maximizing global viewership.
Does Yukon observe PDT?
No. In 2020, the Canadian territory of Yukon stopped changing clocks and adopted permanent Mountain Standard Time (UTC-7), effectively remaining aligned with PDT year-round.
What happens to cron jobs during the fall back transition from PDT to PST?
When clocks fall back from 2:00 AM PDT to 1:00 AM PST on the first Sunday of November, automated scripts scheduled between 1:00 AM and 2:00 AM will run twice unless configured on UTC.
What is the best meeting time between Los Angeles (PDT) and Sydney (AEST)?
With a 17-hour time difference between PDT (UTC-7) and AEST (UTC+10), the optimal meeting window is 4:00 PM – 6:00 PM PDT (which corresponds to 9:00 AM – 11:00 AM next day in Sydney).
How do streaming services handle PDT global releases?
Major entertainment streaming platforms (Netflix, Disney+) release new film and series episodes worldwide at 12:00 AM (midnight) PDT, corresponding to 3:00 AM EDT and 8:00 AM BST.
What is the time difference between PDT and Japan Standard Time (JST)?
Japan Standard Time (JST, UTC+9) is 16 hours ahead of Pacific Daylight Time (PDT, UTC-7). When it is 5:00 PM PDT in San Francisco, it is 9:00 AM the following morning in Tokyo.
Is PDT an official IANA identifier?
PDT is an abbreviation. Software engineering standards use IANA location strings like `America/Los_Angeles` or `America/Vancouver`, which handle PDT transitions automatically.