def checked_at_range_valid?
    if checked_at_from.present? && checked_at_to.present?
      if (/^[0-9]{4}-[0-9]{2}$/ =~ checked_at_from && /^[0-9]{4}-[0-9]{2}$/ =~ checked_at_to) || (/^[0-9]{4}-[0-9]{2}-[0-9]{2}$/ =~ checked_at_from && /^[0-9]{4}-[0-9]{2}-[0-9]{2}$/ =~ checked_at_to)
      
        if checked_at_from > checked_at_to