PDT — Pacific Daylight Time
Daylight variant of PST — UTC-7.
PDT stands for Pacific Daylight Time. Daylight variant of PST — UTC-7.
PDT is UTC-07:00 from Coordinated Universal Time (UTC). The primary IANA zone is America/Los_Angeles.
PDT is a daylight-saving time abbreviation. It is used when clocks are advanced from PST (UTC-08:00) during summer months.
Standard / daylight pair
PST · UTC−8 — November–March in the US and Canada
Countries using this zone
- United States
- Canada
- Mexico
Principal cities
- Los Angeles
- San Francisco
- Seattle
- Vancouver
- Tijuana
- Las Vegas
- Portland
- San Diego
History
The Pacific time zone was officially adopted by the United States Congress with the Standard Time Act of 1918. The current schedule for daylight saving time was established by the Energy Policy Act of 2005, which moved the start date to March and the end date to November. These adjustments were implemented to promote energy conservation across North America and maintain synchronization among regional trade partners. Recently, Yukon transitioned to a permanent year-round offset that aligns with PDT, while most of Mexico discontinued the practice of seasonal shifts.
Frequently Asked Questions
PDT — Pacific Daylight Time. Daylight variant of PST — UTC-7.
PDT is UTC-07:00. It is paired with PST (UTC-08:00).
Countries and territories primarily using PDT include: US, CA.
PDT IS the daylight-saving variant. Zones shift from PST to PDT at the start of summer and back to PST at the end.
PDT is the summer (daylight-saving) abbreviation and PST is the winter (standard) abbreviation. PDT is one hour ahead of PST.
The primary IANA time zone representing PDT is America/Los_Angeles. Operating systems and programming libraries use this identifier to resolve local time.
PDT (UTC−7) is the daylight saving version of PST (UTC−8). Most regions in the Pacific time zone shift to PDT during the warmer months to gain more evening daylight. Current estimates show this transition advances clocks by 1 hour. This shift occurs annually to maximize sunlight usage during the spring, summer, and autumn periods. It is primarily used to align human activity with the longer daylight hours available during these seasons.
PDT begins on the 2nd Sunday of March at 02:00 local time and concludes on the 1st Sunday of November at 02:00 local time. During the spring transition, clocks move forward by 1 hour. In the autumn, the time reverts to standard time as clocks are moved back by 1 hour. This schedule is followed by most of the United States and Canada. Recent data indicates that these transition dates help reduce residential electricity consumption.
While most of Mexico abolished daylight saving time recently, the state of Baja California continues to observe it. This allows border cities like Tijuana and Mexicali to remain synchronized with the Pacific time zone in the United States. Consequently, these regions use PDT (UTC−7) during the same period as their northern neighbors. This synchronization is vital for the integrated economies of the border region.
Several major metropolitan areas use PDT during the summer months. These include Los Angeles, San Francisco, Seattle, and San Diego in the United States. In Canada, Vancouver and Victoria are the primary users. Recent data indicates that the northern Mexican city of Tijuana also observes this time zone to facilitate international trade and travel. These cities represent major hubs for the global tech and media industries.
Arizona does not observe PDT, as most of the state remains on Mountain Standard Time (UTC−7) year-round. This means that during the summer months, Arizona has the same clock time as PDT regions, but it does not technically use the daylight saving designation. Only the Navajo Nation within Arizona observes the seasonal time change. For the rest of the state, clocks do not change in March or November.