Important note: Most cities located in Pacific Daylight Time (PDT) zone observe Daylight Saving Time (DST) during summer. Therefore, most cities there are using Pacific Standard Time (PST). Example of location: San Francisco Use the search bar above to look up by city and not by time zone.

History and Overview

The Pacific Daylight Time zone is seven hours behind Coordinated Universal Time (UTC). The region that this encompasses is the western coast of the United States, specific Canadian provinces, and a Mexican state. There are also other times zones within this same offset that we’ll explore in more detail.

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Join us as we examine this region, the difference between PDT and PST, which locations observe it, and learn some more facts about Daylight Saving Time that you may not already know.

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The Difference Between PDT and PST

During the summer, parts of the world, the United States mostly, observe Daylight Saving Time where the clocks are turned back an hour to allow for more sunlight during the summer months. During this time the offset for this time zone is UTC -7:00. When the winter months arrive and the clocks are set back to their original time, the zone is then designated as Pacific Standard Time (PST).

During the winter months when PST is in effect, the offset is UTC -8:00. Understanding this distinction will help you better convert between time zones, but if you’d rather not do the math, you can also use our extremely helpful time zone converter to do the job for you. If you are looking to get your hands a little dirty, let’s try an example of converting from PDT to EDT, shall we?

Since PDT is seven hours offset from UTC, we need to account for the three hours difference to EDT which is 4 hours offset from UTC. Knowing this allows us to do a quick calculation, keeping in mind that we’re moving forward in time three hours since we’re moving up in the offsets.

So, 10:00AM in PDT would be 1:00PM in EDT. The three hours is added to the time since we’re moving upward in the offset from 7 hours to 4 subtracted from UTC.

Countries and States That Observe PDT

The Pacific Time zone is used in several U.S. States, Canada, and Mexico. Below are locations in each region where PDT is used during the summer months:

CaliforniaWashingtonOregon – all except for the majority of Malheur County on the Idaho border.Nevada – Legally, all of Nevada does, but the border town of West Wendover, and the towns of Jackpot, Jarbidge, Mountain City, and Owyhee all observe Mountain Time because of the proximity to and connections with nearby towns in IdahoIdaho Panhandle – The region of Idaho north of the Salmon River

For Canada PDT is observed in the following locations:

British Columbia – except for the eastern communities of Cranbrook, Golden, and Invermere which are in the MST/MDT zone.Yukon

There is one Mexican State that uses PDT in the summer and PST in the winter. It is Baja California Norte. Before we move on, let’s examine several other time zones that also adhere to the offset of UTC -7:00:

MST – Mountain Standard Time

This time zone has areas that observe DST, at which times of year it is known as MDT. There are actually thirteen states that observe MST during the winter and MDT in the summer. In many of these states however, it is specific locations which observe this time zone.

In Canada, there are five provinces that observe Mountain Standard Time and the DST variation. Again in some of these cases, there are only specific areas that use the time zone. Finally, there are five Mexican states that utilize this zone. Arizona and the Mexican state of Sonora are the only two locations that don’t observe DST and therefore have MST time all year.

T – Tango Time Zone (Military)

This UTC -7:00 time zone is utilized by military aviation. It is most commonly used over the ocean between the longitudes of 112.5 degrees west and 97.5 degrees west. The designation for this time zone is written in military time with “T” being used to show the time zone. An example would be 0800T or “zero eight hundred Tango.”

11 Facts About Daylight Saving Time You Probably Didn’t Know

Since this time zone is reserved for areas that observe DST, here are ten facts about this practice of changing the clocks twice a year that you may not have heard before. Enjoy!

It Started as a Joke

The first time DST came up as an idea was in Benjamin Franklin’s 1784 letter entitled An Economical Project. While he did propose something along the lines of this idea, he was being satirical. In the letter he claims that total of 64 million pounds of wax could be saved in the city of Paris if people woke up with the sun.

To make people wake up earlier he suggested things like taxing people with shutters on their windows, rationing candles, and waking people up with ringing church bells or firing cannons. Clearly he wasn’t being serious, but some people thought it was a good idea anyway.

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It’s Bad For Your Heart

According to studies conducted by hospitals, Daylight Saving Time’s hour change interrupts our circadian rhythms when we sleep and increases stress to the point where heart attacks are far more common than any other time during the year. Following the spring change, local Michigan hospitals reported an increase of heart attacks by as much as 25 percent!

It Thwarted Terrorists Once

Oh yeah, DST actually did something good when it caused a terrorist attack to happen off schedule. In September of 1999 the West Bank was on DST while Israel was on standard time. The terrorists didn’t account for this and set their bomb timers incorrectly to where they went off an hour earlier than expected. Three terrorists were killed as opposed to two busloads of people, which were the targets.

There’s a Reason it Happens at 2 A.M

In case you thought that the chosen was time was completely random, it’s actually not. 2 A.M is the least disruptive time of day for businesses, and it’s the soonest hour after midnight where turning the clock forward or backward won’t change the day.

It Got one Man Out of The Draft

When the Vietnam War was going on, DST managed to save one man from having to go fight overseas. In his state of Delaware, he argued, standard time was the official method for recording birth dates. He argued that he was born a day earlier compared to DST which would have given him a higher draft lottery number. The argument worked, he didn’t have to go to war.

Bars Aren’t Open an Extra Hour

For those who enjoy late nights, you may think that bars will be open an extra hour in the fall when the clocks go back, but state laws have found ways around this. For example, in California bars are required to close at 1:59 A.M which is one minute before DST ends each fall. Other states word it as “two hours after midnight.” which would negate the ability for them to stay open late.

DST Began in The U.S During WWI

The United States first started using DST during WWI when President Woodrow Wilson wanted to limit coal consumption. After the war, he wanted to keep the practice in place but Congress repealed the plan, even going so far as to override a presidential veto!

It Sent Clock into Chaos

In WWII, DST caused what time magazine called “a chaos of clocks.” Up until 1966 the states and governments within good start and end their DST whenever they felt like it. During one period of time you could ride on a train from Ohio to West Virginia and travel through seven different time changes!

There’s No “S”

The official title is Daylight Saving Time, not Daylight Savings Time. Despite this distinction, there are millions of searches each year online for both variations.

Not Every U.S. State Observes it

There are only 48 states that observe DST. The states of Arizona and Hawaii have standard time throughout the year. The Navajo Nation in Arizona still observes DST however.

It Still Makes People Late

Despite the fact that most electronic clocks on phones and other devices change automatically, people are still often late or early on the days that the time changes. A Rasmussen Report showed that 27% of Americans admitted to the time change making them early or late.

Is DST Going Away Anytime Soon?

There has been a seemingly ongoing war happening over whether DST is something we should keep around or something that should have ended with the last world war. Washington state, a current participant in the practice is beginning to show signs of joining the admittedly small list of states that do not follow the practice. Does this mean other states in the PDT zone will follow suit?

A bill proposed to the state government in February of 2015 brings many of the arguments against the practice to light. Five other states including Oregon have begun making similar pursuits, leading to the question of whether or not this practice will last much longer after all the opposition it has faced.

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Only time will tell, but for now, there are still several U.S. States and countries that following the change to PDT during the summer months of the year.

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