From 1970 until 2006, most of Indiana in the Eastern Time Zone did not observe daylight saving time, but the entire state started to do so in April 2006 after eight counties in western Indiana were shifted from the Central Time Zone to the Eastern Time Zone.[30] One goal for observing DST was to get more Indiana counties observing the same time zone; formerly, 77 counties observed EST, 5 observed EST/EDT (the EDT usage being unofficial only), and 10 observed CST/CDT. As of 2016, Indiana has 12 counties observing Central Daylight Time while the remaining 80 counties observe Eastern Daylight Time. Those counties observing CST are in two groups: one near or in the Chicago metropolitan area, and the other around Evansville in the southwest corner of the state.