Learning the twists and turns of time zones

Nancy Sullivan’s sixth-graders at Frederick Nerge Elementary in Roselle wanted to know, “How are the time zones determined?”

Travel back in time about 100 years and you’d find that time had more to do with individual taste than collaboration.

“Well into the 19th century, each town had its own time based on where the sun was overhead, which made a noticeable difference in time when traveling east to west,” said George Ritzlin, owner of George Ritzlin Antique Maps & Prints in Evanston.

At one point, there were 300 local time zones across America. The U.S. railway boom in the 1830s and the stampede of settlers seeking land and gold prompted the need for standardized time in the U.S. and Canada. Vast expanses of land could mean a tangle of different time zones.

An 1884 international conference held in Washington, D.C., created 24 time zones worldwide that generally follow the earth’s 24 meridians or longitudinal lines.

“At the conference, it was accepted that Greenwich, England, would be the prime meridian,” Ritzlin explained.

Starting with the prime meridian, the hours increase by one when traveling west, returning to the Prime Meridian at 24 hours.

Political reasons sometimes dictate how the clock is set. Some countries ignore time zones and opt instead for one standard time. At one time, China was divided into five time zones, but now it falls under one standard time. India stretches across 28 longitudinal lines but also uses only one time zone throughout the country.

The U.S. has eight time zones, including Alaska, Hawaii and Samoa.

Time is synchronized using Universal Time, Coordinated, also known as UTC and Greenwich Mean Time. An atomic clock at the U.S. Naval Observatory in Washington, D.C., precisely keeps time for the world. When it’s midnight UTC, it’s 6 p.m. at home in the Central Standard Time Zone.

Time can fly, but when it comes to aligning with the meridians, it is known to twist and turn. The Central Standard Time Zone includes Chicago and northwest and southwest Indiana. Indiana’s middle section, however, neatly fitting between its northern and southern parts, follows Eastern Standard Time.

For timely information on the time in any location, refer to the website www.timeanddate.com.