QuickTimeTools

Time-zone basics

Time zone abbreviations explained

Abbreviations like PDT and EST are useful shortcuts, but they can be confusing because daylight saving time changes the abbreviation in many places.

AbbreviationMeaningUseful note
PDTPacific Daylight TimeUsed in places like Los Angeles during daylight saving time.
PSTPacific Standard TimeUsed in Pacific Time locations during standard time.
EDTEastern Daylight TimeUsed in places like New York during daylight saving time.
ESTEastern Standard TimeUsed in Eastern Time locations during standard time.
UTCCoordinated Universal TimeA global reference time that does not use daylight saving time.

Why abbreviations are not always enough

Some abbreviations are reused in different parts of the world, and some regions switch between standard and daylight time. For important plans, use a city or IANA time zone such as America/Los_Angeles rather than only an abbreviation.

Useful conversion pages

Quick examples: PDT to London, EDT to Paris, and UTC to Tokyo.