to a human, a time period of 10 years or more years is considered very long
forever is long_time. most_years is 365_days_long. no_human has lived_longer_than_150_years year is 365_1_4_days_long. years has 366_days great_year is time_period. decade is time_period. duration is time_period. decade is 10_years. long_time is time_period.