The PST and PDT always follow one another in the calendar year. Several states in the United States, Canada, and Mexico follow PST and PDT.
The main contrast between PST and PDT is that PST is used between November and mid-March, but PDT is used from mid-March to November. In brief, PST is being used in the Winter, and PDT is used in the summers of a calendar.
Adding one letter in the middle of each term changes things, and what does it mean?

Comparison Chart

BasicPacific Standard TimePacific Daylight Time
DefinitionTime followed during the Winter.       Time is followed during the Summer.
Stands ForPSTPDT
CountriesMexico, Canada, and US.                  PST occurred
Time Framefrom Early November to Mid-MarchEarly November to Mid-March.
Time Difference         It is the standard time and, it will not change.Time is kept one hour before PST.
UTC8 hours behind           7 Hours Behind
GoalTo indicate the time about GMT or UTC.To save daylight time during the summertime.
BenefitsWinter Days are shorter        Longer Summer days

What is PST?

Pacific Standard Time is known as PST too. Two states in the United States of America are entirely under Pacific Standard Time, California and Washington.

There is only one region completely in the Pacific Time Zone, Yukon. In the Winter, the Mexican state of Baja also follows PST. Even during the Winter season, it is the standard time followed.

Ideally, from early November through the middle of March, they should maintain Pacific Daylight Time. The Pacific Standard Time is 8 hours ahead of Universal Time in the winter Pacific Daylight Time is observed in the Winter to shorten the day.

PST is the time for the duration of the Winter as it is the standard time, so it remains the same.

What is PDT?

PDT is named Pacific Daylight Time. In places where PST is observed, it increases the day during the summertime in the United States, Canada and Mexico.

During the Summer, the clocks are forward one hour. Every year on the second Sunday in March, it begins. It comes to an end during the first week of November each year, when the clocks are set back one hour. To maximize day utilization, this is performed to move the clock forward. The clocks are again turned around by an hour during fall time.

The standard time is set one hour ahead of Pacific Standard Time. It improves in saving energy throughout the day. On the First Sunday in November, PDT is changed to PST. The time change traditionally occurred between the first Sunday of April and the last Sunday of October.

Key Differences Between PST And PDT

  1. The primary difference between PST and PDT is that PST is used in the winter, and PDT is used in the summer.
  2. Accordingly, the abbreviations PST and PDT stand for Pacific Standard Time and Pacific Daylight Time.
  3. In the United States of America, Pacific Standard Time starts in early November and lasts until the middle of March the following year.
  4. During the first two months of spring and the first two months of fall, Pacific Daylight Time (PDT) begins and ends.
  5. The winter days for people in the Pacific Daylight Time run shorter than those in the Pacific Standard Time (PST).
  6. PST is eight hours before Coordinated Universal Time (UTC-8), and PDT is seven hours ahead.
  7. Using PDT, the time is advanced by one hour, but when PST has been used again, the time is run by one hour.
  8. In the summer, PDT is utilized to save energy, whereas PST is used in the winter when the days are short.
  9. PST is used to indicate the time about GMT or UTC. On the other hand, the goal of PDT is to save daylight time during the summertime.
  10. British Columbia and Yukon are two Canadian provinces that use PDT during the summer and PST the rest of the year.
  11. For the purpose of keeping longer days, PDT starts one hour earlier than PST
  12. PDT is kept one hour behind PST as the usual time during the summer.
  13. PST is observed according to the next calendar year, whereas PDT follows the current year.
  14. PDT and the PST time zone are shared by many states, yet everyone must adjust their clocks accordingly.


The world revolves around the sun; one side experiences daylight at one moment while the other experiences night and this cycle continue throughout the year. Standard time is used in the United States and Canada from late autumn to early spring (PST), and daylight-saving time is observed from early spring to late fall (PDT).

In regions that use Pacific Time, both PST and PDT are being used (PT). Remembering the time change is as simple as saying “spring forward, fall back.” These time modifications take occur in March and November. It is centered on the Greenwich Observatory’s 120th meridian west.

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