shoulder peak
 n.— «Niagara Mohawk Power Corporation…Proposed rate periods:…On Peak: 5:01 p.m. to 8 p.m., weekdays. Shoulder Peak: 9:01 a.m. to 5 p.m., weekdays.» —“Time-Of-Use Rate Plan For Residential Customers Filed” PR Newswire Mar. 15, 1989. (source: Double-Tongued Dictionary)