What Do PT and ET Mean? Reading Time Zone Abbreviations and Converting Release Times to Japan Time

What the common abbreviations mean

The abbreviations used in international announcements combine a region with “standard time or daylight saving time”. For example, PST is Pacific Standard Time and PDT is Pacific Daylight Time. When referring to both together, it’s written PT.

• If the middle letter is S, it’s standard time; if it’s D, it’s daylight saving time. That’s the only difference between PST and PDT, and it shifts the offset by an hour.
• Writing PT, ET or CT without the S or D means “the current local time in that region”. Which one applies depends on the date.
• UTC is Coordinated Universal Time, the reference for time zone calculations. Japan is fixed at UTC+9.
• GMT is used almost interchangeably with UTC, but it also means the UK’s standard time. The UK switches to BST (UTC+1) in summer, so “it says GMT, so it’s always UTC+0” isn’t necessarily true.

Daylight saving shifts the difference by an hour

Japan has no daylight saving time, so its time difference with other countries changes twice a year. If you remember it as “always 17 hours”, you’ll book things an hour off around the changeover.

• Even in the US, Hawaii and most of Arizona don’t observe daylight saving. Their difference stays the same all year.
• Australia is in the Southern Hemisphere, so its daylight saving runs opposite to Japan’s summer and winter. Whether it’s used also differs between states.
• China, India, Singapore and South Korea have no daylight saving time. Their difference from Japan is constant year-round.
• Countries can change their daylight saving rules. When planning far ahead, it’s safest to check again shortly before.

How to convert to Japan time

1. 1

   Read the UTC offset from the abbreviation

   For “10:00 AM PDT”, PDT is UTC−7. If it just says “PT” without S or D, decide by whether the date falls within daylight saving time.

2. 2

   Work out the difference from Japan

   Japan is UTC+9, so subtract the other offset from 9. For PDT (UTC−7), 9 − (−7) = 16, so Japan is 16 hours ahead.

3. 3

   Add the difference to the local time

   10:00 plus 16 hours is 26:00. Anything over 24 rolls over to the next day, so in Japan time it’s 2:00 the next day.

4. 4

   Check the date rollover

   The difference with the US is 13–17 hours, so as a rule, a local morning is the same evening in Japan, and a local afternoon is the next day in Japan. Check the day of the week too.

Check the current time with a tool

If you’re not sure your calculation is right, the reliable way is to look at the current times side by side. The World Time Zones tool shows the current time in 13 countries and regions including Japan, along with each one’s difference from Japan.

1. 1

   Find the city you need

   It shows New York (Eastern Time) for the US, London for the UK, and Paris and Berlin for continental Europe. All differences are shown relative to Japan time.

2. 2

   Use the displayed difference to check your answer

   Daylight saving is applied automatically, so you can see how many hours apart you are right now. If it doesn’t match your calculation, you may have misjudged daylight saving.

3. 3

   Work out cities not on the list from the difference

   The US West Coast isn’t on the list, but you can get it by subtracting 3 hours from Eastern Time. If New York is 13 hours behind Japan, Los Angeles is 16 hours behind.

4. 4

   Judge future dates yourself

   It shows the current time, so for events months away, check yourself whether they fall within daylight saving. If a changeover date comes in between, today’s difference won’t necessarily apply.

Dealing with confusing notation

• CST is used for both North American Central Standard Time (UTC−6) and China Standard Time (UTC+8). If the context doesn’t make it clear, infer it from where the sender is based.
• IST refers to both India Standard Time (UTC+5:30) and Irish Standard Time (Ireland’s summer time). It’s also easy to miss that India’s offset is in half hours.
• In 12-hour notation, “12:00 AM” is midnight, not noon; “12:00 PM” is noon. Mix them up and you’re 12 hours off.
• If it only says “PT” or “ET” and the date is near a daylight saving changeover, ask the organizer or look for notation with a UTC offset.
• If the event page has something like “2026-10-15T18:00-07:00”, that’s the most reliable. The −07:00 at the end is the UTC offset itself.

FAQ

What’s the difference between PT, PST and PDT?

PST is Pacific Standard Time (UTC−8) and PDT is Pacific Daylight Time (UTC−7). PT covers both, and which one applies depends on the date. In the US, daylight saving runs from the second Sunday in March to the first Sunday in November, so “PT” during that period means PDT. The difference from Japan is 17 hours for PST and 16 hours for PDT.

What time is “9 PM ET” in Japan?

During daylight saving time (second Sunday in March to first Sunday in November) it’s EDT (UTC−4), 13 hours behind Japan, so it’s 10:00 the next day. At other times it’s EST (UTC−5), 14 hours behind, so it’s 11:00 the next day. Decide which period applies from the event’s date.

Does Japan have daylight saving time?

Japan currently has no daylight saving time. Japan Standard Time (JST) is fixed at UTC+9 all year. So the time difference with other countries only changes when they switch their clocks. Just remember that twice a year there are periods when the difference shifts by an hour.

What if I can’t tell what an abbreviation refers to?

First check where the sender is based. An abbreviation like CST, used for both North American Central Standard Time and China Standard Time, can be pinned down once you know the region. If you still can’t tell, the reliable approach is to look for notation with a UTC offset (such as −07:00) or a countdown on the event page.