Era of liberalization

• Decade when ZIP codes were introduced
• Hippie decade
• "Flower power" period
• "The Help" era, with "The"
• Number of fashion items in Mary Quant's era
• The time of life between 60 and 70
• Hippie era, with 'The'

Wiktionary Word definitions in Wiktionary
alt. 1 (sixty English) 2 The decade of the 1860s, 1960s, etc. 3 The decade of one's life from age 60 through age 69. n. 1 (sixty English) 2 The decade of the 1860s, 1960s, etc. 3 The decade of one's life from age 60 through age 69.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Sixty \Six"ty\, n.; pl. Sixties . The sum of six times ten; sixty units or objects. A symbol representing sixty units, as 60, lx., or LX.