Example of an algorithm to get years, months, days between two days (expressed in two ways)

time_parts.rb

require "time"

p now = Time.parse("2020-08-07")
p date = Time.parse("2013-08-07")
delta, _ = (now.to_i - date.to_i).divmod(24 * 60 * 60)

years, rest = delta.divmod(365)
months, days = rest.divmod(30)
puts "years: #{years}"
puts "months: #{months}"
puts "days: #{days}"

# years: 7
# months: 0
# days: 2

require "active_support/all"
puts "active_support"
delta = now - date

years, rest = delta.divmod(1.year)
months, rest = rest.divmod(1.month)
days, rest = rest.divmod(1.day)
puts "years: #{years}"
puts "months: #{months}"
puts "days: #{days}"

# years: 7
# months: 0
# days: 0