1. (noun) a period marked by distinctive character or reckoned from a fixed point or event

• era

2. (noun) (astronomy) an arbitrarily fixed date that is the point in time relative to which information (as coordinates of a celestial body) is recorded

• date of reference

1. (noun) a period marked by distinctive character or reckoned from a fixed point or event

• age
• historic period
• day
• modern era

1. (noun) (astronomy) an arbitrarily fixed date that is the point in time relative to which information (as coordinates of a celestial body) is recorded

• astronomy
• uranology

1. (noun) a period marked by distinctive character or reckoned from a fixed point or event

• period
• period of time
• time period

2. (noun) (astronomy) an arbitrarily fixed date that is the point in time relative to which information (as coordinates of a celestial body) is recorded

• date

3. (noun) a unit of geological time that is a subdivision of a period and is itself divided into ages

• geologic time
• geological time

1. (noun) a period marked by distinctive character or reckoned from a fixed point or event

• epoch-making
• epochal