activesupport/lib/active_support/core_ext/time/calculations.rb
Required Files
active_support/
duration active_support/
core_ext/ time/ conversions active_support/
time_with_zone active_support/
core_ext/ time/ zones active_support/
core_ext/ date_and_time/ calculations active_support/
core_ext/ date/ calculations active_support/
core_ext/ module/ remove_method