Related Clues:

• Times are bad - start saving!
• The times are changing, son
• Deliver a sermon, taking ages
• Divisions of eons
• How often, at most, one can be elected U.S. president
• Important stretches
• The Eisenhower years and others
• They're historical
• How the careful think
• Times long gone?
• Important blocks of time
• Presidential administrations, e.g
• Figs. always expressed to two decimal places
• Geologic slices of time
• Schoolmaster assists only some of these characters in periods