Read this and answer the question. If the question is unanswerable, say "unanswerable".

The history of time in the United States includes DST during both world wars, but no standardization of peacetime DST until 1966. In May 1965, for two weeks, St. Paul, Minnesota and Minneapolis, Minnesota were on different times, when the capital city decided to join most of the nation by starting Daylight Saving Time while Minneapolis opted to follow the later date set by state law. In the mid-1980s, Clorox (parent of Kingsford Charcoal) and 7-Eleven provided the primary funding for the Daylight Saving Time Coalition behind the 1987 extension to US DST, and both Idaho senators voted for it based on the premise that during DST fast-food restaurants sell more French fries, which are made from Idaho potatoes.

What year did the U.S. see standardization of DST outside of wartime for the first time?
1966