Related Clues:

• Sections of a natural history museum, maybe
• History book sections, say
• Geologists' periods
• Paleozoic and Edwardian, e.g
• Long periods of history
• Presidential terms, perhaps
• Fashion periods
• ". . . for children of all ___!"
• Meaningful stretches of history
• Turns mellower
• Time-line slices
• Cenozoic and Big Band
• Interesting historical periods
• "Rock of __"
• Yonks