Daylight Saving Time
When we change our clocks
Rationale and original idea
First there was Standard time
Early adoption and U.S. law
Worldwide daylight saving
Worldwide daylight saving
Worldwide daylight saving
Changes and irregularities

Embargo changes

During the Arab-Israeli War in October 1973, Middle East members of OPEC issued an embargo against the sale of crude oil to Israel's Western allies. In the United States, gasoline became scarce and prices jumped 40 percent, crimping the American economy. Following the 1973 Arab Oil Embargo, Congress put most of the nation on extended Daylight Saving Time for two years in hopes of saving additional energy. This experiment worked, but Congress did not continue the experiment in 1975 because of opposition -- mostly from the farming states.

In 1974, Daylight Saving Time lasted ten months and lasted for eight months in 1975, rather than the normal six months (then, May to October). The U.S. Department of Transportation -- which has jurisdiction over Daylight Saving Time in the U.S. -- studied the results of the experiment. It concluded:

Daylight Saving Time saves energy. Based on consumption figures for 1974 and 1975, The Department of Transportation says observing Daylight Saving Time in March and April saved the equivalent in energy of 10,000 barrels of oil each day -- a total of 600,000 barrels in each of those two years.

Daylight Saving Time saves lives and prevents traffic injuries. The earlier Daylight Saving Time allowed more people to travel home from work and school in daylight, which is much safer than darkness. And except for the months of November through February, Daylight Saving Time does not increase the morning hazard for those going to school and work.

Daylight Saving Time prevents crime. Because people get home from work and school and complete more errands and chores in daylight, Daylight Saving Time also seems to reduce people's exposure to various crimes, which are more common in darkness than in light.

The Department of Transportation estimated that 50 lives were saved and about 2,000 injuries were prevented in March and April of the study years. The department also estimated that $28 million was saved in traffic accident costs.

Congress and President Reagan change Daylight Saving Time

Daylight Saving Time was changed slightly in 1986 when President Reagan signed Public Law 99-359. It changed Daylight Saving Time from the last Sunday in April to the first Sunday in April. No change was made to the ending date of the last Sunday in October.

This was done ostensibly to conserve energy during the month of April. Adding the entire month of April is estimated to save nationwide about 300,000 barrels of oil each year.


96mapWhat time is it when the Indiana capital is noon?

Indiana is one of three U.S. states which do not Spring ahead from "standard" to "daylight saving" time or Fall back from daylight to standard six months later. Arizona and Hawaii are the others. By State Law, most of Indiana is on Eastern Standard Time (EST) all year long.

The statute creates three different time arrangements in the Hoosier State:

  1. 77 counties (including state capital Indianapolis) are in the Eastern Time Zone but do not change to Daylight time in April; instead they remain on Standard Time all year long; [yellow on map and chart]
  2. 10 counties -- five near Chicago, IL, and five near Evansville, IN, are in the Central Time Zone and use both Central Standard and Central Daylight; [green on map and chart] and
  3. five other counties -- two near Cincinnati, OH, and three near Louisville, KY -- are in the Eastern Time Zone but use both Eastern Standard and Eastern Daylight. [pink on map and chart]

Locations During U.S. standard time During U.S. daylight saving time
Central Indiana (1) Indianapolis, and most of Indiana, including Bloomington Noon
Eastern Standard
Eastern Standard
Western portions of Indiana (2) Chicago, IL and Jasper, Lake, LaPorte, Newton, and Porter counties 11:00 AM
Central Standard
Central Daylight
Evansville, IN and Gibson, Posey, Spencer, Vanderburgh, and Warrick counties
Eastern portions of Indiana (3) Cincinnati, OH and Dearborn and Ohio counties Noon
Eastern Standard
1:00 PM
Eastern Daylight
Louisville, KY and Clark, Floyd and Harrison counties

Many believe that Indiana changes time zones in the Summer. Part of the confusion stems from the fact that in the Winter, most of Indiana is the same time as New York (which is also Eastern), and in the Summer, Indiana is the same time as Chicago (which is Central).

Actually, by going to Daylight time in April, the Central Zone Springs ahead from Standard to CDT, which is the same as Eastern Standard (Indiana time). By switching from Eastern Daylight (EDT) to Standard in October, the rest of the Eastern Zone Falls back to EST (Indiana time). Indiana, Arizona, and Hawaii are constants -- always Standard time.

Courtesy the Monroe County Community School Corporation, Bloomington, IN 47401. Please send questions or comments specifically about Indiana to

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