Uniform Time Act - Definition and Overview

In the United States, the Uniform Time Act is a federal law, enacted in 1966, whose effect was to simplify the official pattern of where and when Daylight saving time (DST) is applied within the U.S.

Previous to this law, each state worked out its own scheme for the dates of beginning and ending DST, and in some cases, which parts of the state should use it.

Since the act's date of effectiveness, states that apply DST at all officially

• apply it to the whole state,
• begin it at 2 AM on the first Sunday in April, and
• end it at 2 AM on the last Sunday in October.

While there are a few areas where de facto differences within states exist, the overall pattern is simple enough, and close enough to actual practice, that it is effective and efficient

• for repeat travelers, and repeat users of long-distance telephone service, to learn the basic pattern, and
• for those in areas where de facto exceptions apply to mention the fact to those likely to be affected by it.