Cover image for On time : from seasons to split seconds
On time : from seasons to split seconds
Skurzynski, Gloria.
Personal Author:
Publication Information:
Washington, D.C. : National Geographic Society, [2000]

Physical Description:
41 pages : color illustrations, color maps ; 29 cm
Examines the ways humans have measured time throughout history and discusses the various units that are used to keep track of it.
General Note:
Includes index.
Reading Level:
1040 Lexile.
Program Information:
Reading Counts RC 6-8 7.5 5 Quiz: 21975 Guided reading level: NR.
Format :


Call Number
Material Type
Home Location
Item Holds
QB209.5 .S53 2000 Adult Non-Fiction Non-Fiction Area-Oversize
QB209.5 .S53 2000 Juvenile Non-Fiction Open Shelf

On Order



A fascinating tour of time measurement through the ages. Children discover how humans learned to recognize time and began to measure it in smaller and smaller units from the precisely placed boulders at Stonehenge, which marked the equinoxes; to Egyptian obelisks, which measured the hours; to modern-day atomic clocks, which subdivide seconds.

Author Notes

Author Gloria Skurzynski was born in Duquesne, Pennsylvania in 1930. She was educated at Carlow University. She writes both fiction and non-fiction books for children and young adults.She is the author of more than sixty books for young readers. In 1992, her work Almost the Real Thing: Simulation in Your High-Tech World won the American Institute of Physics Science Writing Award. She writes the National Geographic National Parks series and the Virtual War Chronologs series.

(Bowker Author Biography)

Reviews 2

Booklist Review

Gr. 2^-5. As we enter a new millennium, the concept of time and its divisions fascinates many of us. On Time discusses the astronomical causes of seasons, years, months, and days, and how people through history have devised increasingly accurate calendars and clocks to keep track of time. Anecdotes, such as Columbus' predicting an eclipse, give a human side to a scientific subject. The illustrations are primarily photographs--some more evocative than informative. Betsy and Giulio Maestro's The Story of Clocks and Calendars [BKL Je 1 & 15 99] covers much of the same information in greater detail, but current preoccupation with the topic may make both titles of value. --Catherine Andronik

School Library Journal Review

Gr 4-7-This attractive offering is brimming with information about time and timekeeping, from seasons, years, and time zones to pendulums, hourglasses, and femtoseconds. The conversational tone helps readers get through the more difficult concepts, such as looking backward into deep time and deep space. Readers get a historical glimpse at the Tower of Winds, a laborious water clock built in Greece in 50 B.C. and Christopher Columbus's clever use of a lunar eclipse to win over the Haitian natives. Although the traditional "B.C." and "A.D." divisions are discussed, the more current "B.C.E." and "C.E." are not mentioned. The fact that hours, weeks, and months are man-made divisions is clearly explained. Skurzynski states that our January 1, 2000 occurs during the Hebrew year 5760 and the Islamic year 1420 A.H. The book is heavily illustrated with full-color drawings, photographs, and diagrams. It could be paired with Gillian Chapman's excellent Exploring Time (Millbrook, 1995), which offers related activities. On Time will find audiences with report writers and pleasure readers, as well as their teachers.-Anne Chapman Callaghan, Racine Public Library, WI (c) Copyright 2010. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.