An illustration shows a clock.

What’s the difference between EST and EDT (or PST and PDT)?

Ah, Daylight Savings Time! I appreciate every minute of that extra hour we gain in the fall. It’s the spring version, when we lose an hour, that always messes with my head. I think many people are often confused by the abbreviations, so I’ll give you an easy way to remember which one to use.

Daylight Savings Time (DST) begins in the spring and ends in the fall (remember: “spring ahead” and “fall back”). Once we hit the fall, we go back to standard time. EDT, CDT, MDT, and PDT refer to U.S. time zones during daylight savings: Eastern Daylight Time, Central Daylight Time, Mountain Daylight Time, and Pacific Daylight Time. Similarly, EST, CST, MST, and PST stand for Eastern Standard Time, Central Standard Time, Mountain Standard Time, and Pacific Standard time.

You should use EDT/CDT/MDT/PDT during the summer months (I always associate “daytime” with “summer” to remember which one to use) and EST/CST/MST/PST during fall/winter/early spring.

So, don’t forget to turn your clocks back an hour before you head to bed tonight–and make sure you use standard time in your U.S. time zone abbreviations until the spring!