prev_week(day = :monday)
public
Returns a new Time representing the start of the
given day in the previous week (default is
Monday).
# File activesupport/lib/active_support/core_ext/time/calculations.rb, line 180
def prev_week(day = :monday)
ago(1.week).beginning_of_week.since(DAYS_INTO_WEEK[day].day).change(:hour => 0)
end