module DateAndTime::Calculations
def last_hour(date_or_time)
def last_hour(date_or_time) date_or_time.acts_like?(:time) ? date_or_time.end_of_day : date_or_time end
def last_hour(date_or_time) date_or_time.acts_like?(:time) ? date_or_time.end_of_day : date_or_time end