Depends. Many office roles start at 8am-4pm, some 9am-5pm.
PCs work on a shift pattern, currently 2x earlies (7am), 2x mids (3pm) and 2x lates (10pm), varying on weekend days, 9-12hr days, paid lunch breaks.
PCSOs work on a shift pattern, until recently, 2x earlies (7am-5pm), 2x mids (11am-8pm) and 2x lates (2pm-midnight). Unpaid lunch breaks, which often get worked through. Although, this is now irrelevant as all Norfolk PCSOs were made redundant in March 2018.
Flexible working patterns can be applied for.