Ask Difference

PDT vs. PST — What's the Difference?

By Tayyaba Rehman — Published on November 7, 2023
PDT stands for Pacific Daylight Time, an hour ahead of PST. PST means Pacific Standard Time.
PDT vs. PST — What's the Difference?

Difference Between PDT and PST


Key Differences

PDT and PST both refer to time zones that are observed in the Pacific Time Zone of the United States and Canada. PDT, or Pacific Daylight Time, is used during the period of Daylight Saving Time, which typically begins from the second Sunday of March and ends on the first Sunday of November. During this time, clocks are set one hour ahead to make better use of daylight in the evenings.
On the other hand, PST, which stands for Pacific Standard Time, is the standard time observed when Daylight Saving Time is not in effect. This means, during the colder months when the days are shorter, the Pacific Time Zone reverts to PST. Both PDT and PST have the same base time, but the difference lies in the adjustment for daylight saving.
The main purpose behind the existence of both PDT and PST is to make better use of daylight during the longer days of summer. By moving the clock forward by an hour, people can have more daylight in the evening, potentially reducing the need for artificial lighting and saving energy.
In essence, PDT and PST are two sides of the same coin. Both are mechanisms to regulate time in the Pacific Time Zone, with PDT giving an extra hour of daylight in the evenings during the warmer months, and PST setting the standard time for the rest of the year.

Comparison Chart

Full Form

Pacific Daylight Time
Pacific Standard Time


Used during Daylight Saving Time
Used when Daylight Saving is not active


1 hour ahead of PST
1 hour behind PDT


Maximize daylight during longer days
Standard time during shorter days


Typically March to November
Typically November to March

Compare with Definitions


Pacific Daylight Time observed during Daylight Saving Time in the Pacific Time Zone.
During the summer, California follows PDT.


Time zone that's one hour behind Pacific Daylight Time.
It gets darker earlier in PST.


The time zone used when days are longer to make better use of daylight.
It's 8 PM PDT, but it's still bright outside!


The regular time zone for the West Coast of the US and parts of Canada.
Her watch is set to PST year-round.


An adjusted time zone that's an hour ahead of Pacific Standard Time.
She set her clock forward to match PDT.


The default time for areas like California, Washington, and British Columbia outside of Daylight Saving.
The webinar starts at 10 AM PST.


A temporary shift from PST to save energy by reducing artificial light usage.
We'll switch to PDT next Sunday.


Pacific Standard Time observed in the Pacific Time Zone when Daylight Saving Time is not active.
Washington State operates on PST during the winter months.


A time representation used predominantly on the west coast of North America.
Make sure your devices automatically adjust to PDT.


A standard reference for scheduling in the Pacific regions of North America.
The meeting is set for 3 PM PST.


Alternative form of psst


Standard time in the 8th time zone west of Greenwich, reckoned at the 120th meridian west; used in far western states of the United States

Common Curiosities

When do we switch from PST to PDT?

The switch typically happens on the second Sunday of March.

Do all states in the Pacific Time Zone observe both PDT and PST?

Most do, but not all. For instance, Arizona doesn't observe Daylight Saving Time.

Does PST stand for Pacific Summer Time?

No, PST stands for Pacific Standard Time.

What's the difference between PDT and PST?

PDT is used during Daylight Saving Time, while PST is used when it's not.

When do we revert from PDT to PST?

This usually occurs on the first Sunday of November.

Do all devices automatically switch between PDT and PST?

Most modern devices do, but it's essential to check and adjust manually if needed.

How many hours difference is there between PDT and PST?

There's a 1-hour difference, with PDT being an hour ahead.

How long does the PDT period last?

It typically lasts from the second Sunday of March to the first Sunday of November.

What does PDT stand for?

PDT stands for Pacific Daylight Time.

Why do we have both PDT and PST?

They help regulate time to make better use of daylight and save energy.

Is Daylight Saving Time observed worldwide?

No, its adoption varies by country and even within regions of countries.

Can PDT be referred to as UTC-7?

Yes, during Daylight Saving Time, the Pacific Time Zone is UTC-7.

Which comes first in the year, PDT or PST?

PDT, as it starts in March, and we revert to PST in November.

Can I keep my clock on PST all year?

Technically yes, but you'll be out of sync with local time during Daylight Saving Time.

What is the UTC offset for PST?

PST has a UTC offset of UTC-8.

Share Your Discovery

Share via Social Media
Embed This Content
Embed Code
Share Directly via Messenger

Author Spotlight

Written by
Tayyaba Rehman
Tayyaba Rehman is a distinguished writer, currently serving as a primary contributor to As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.

Popular Comparisons

Trending Comparisons

New Comparisons

Trending Terms