Short answer: when the clocks change, a commercial site should confirm which time governs every security shift, access schedule, alarm window, CCTV timestamp and welfare check. Record the expected time, the observed time, any correction and the person responsible for rechecking it. Do not assume that every system updates automatically or that “the night shift knows” how the repeated or missing hour will be covered.
In the UK, the clocks went back at 2am on Sunday 25 October 2026, returning to 1am. The government publishes the current timetable in its clocks-change guidance. That one-hour change can expose unclear roster instructions or mismatched equipment settings, particularly on sites operating overnight.
This article is general planning guidance for commercial premises. The site’s contracts, risk assessment, working-time arrangements, emergency plan and manufacturer instructions still apply. Detailed access rules, system configurations and vulnerabilities should remain in controlled documents.
Set the time basis before the shift starts
The client or site manager should state the operational time zone and the exact moment at which the roster changes. A written instruction such as “01:00 GMT after the clock change” is clearer than “the second 1am” or “normal time”. The same precision should appear in relief arrangements, contractor permits and monitoring instructions.
Confirm who covers the repeated hour when the clocks go back, or the missing hour when they go forward. The employment and payment implications belong with the relevant employer and contract owner; a security officer should not be left to resolve them at the gatehouse. Any change to contracted coverage should be authorised before the duty begins.
The Health and Safety Executive identifies shift handover as a safety-critical communication and says organisations should allow time and set standards for handovers. Its guidance on safety-critical communications is a useful basis for deciding what must be passed between the outgoing and incoming duty.
Check the handover record and incident chronology
A repeated hour can make two events appear to have happened at the same time. The handover record should therefore distinguish the time zone or otherwise follow the organisation’s approved convention. Keep one consistent approach across the shift log, incident reports and supervisor communications.
Do not rewrite an original entry merely to make the sequence look neater. If a timestamp is later found to be wrong, preserve the factual record and add a traceable correction in line with the site’s reporting procedure. The aim is a chronology that another authorised person can understand without guesswork.
Review access-control schedules
Electronic access control may use the controller’s local time, a server time, a cloud service or a separate building-management clock. Confirm that authorised opening periods, contractor access, visitor permissions, gate schedules and any temporary exceptions still begin and end when intended.
A security officer can observe and report the operational result assigned to them, but system changes should remain with the authorised administrator. Avoid publishing door names, credential groups or fallback arrangements. If a schedule is wrong, record the issue, apply the approved contingency and give the correction to a named system owner.
Where a site uses guarding, alarms, CCTV or access-control measures together, the review should cover the links between them as well as each system separately. A gate schedule that changes at the right time is not enough if the associated visitor instruction or alarm window still uses the old time.
Confirm alarm and escalation windows
Check planned setting and unsetting periods, monitored hours, authorised call lists and the times at which escalation responsibility passes between people or teams. A clock change does not authorise an officer to silence, reset or reinstate an alarm outside the agreed assignment and authority.
If the site uses automatic schedules, verify the expected result after the change rather than relying only on a configuration screen. If the result is unexpected, preserve the event information and use the approved escalation route. The guide to authorised alarm resets explains why investigation, silencing, resetting and returning protection to service should be treated as separate decisions.
Sample-check CCTV and recorded time
For CCTV or other video systems, an authorised administrator should compare the displayed live time with the expected local time and check a short recording or export. The recorder, individual cameras and viewing software may not all use the same time source. A visible clock on one screen does not prove that every recorded stream is aligned.
If there is a mismatch, document the observed offset, the period it may affect and the person responsible for correction. Do not delete footage or alter an evidential record to hide the discrepancy. Access to recordings and exports should stay restricted to authorised people.
The Information Commissioner’s Office provides current guidance on video surveillance, including CCTV. The organisation should continue to follow its documented purpose, access controls, retention arrangements and data-protection responsibilities while resolving any timestamp problem.
Reconfirm lone-worker and welfare contacts
If a security officer works alone, make sure check-in times, missed-contact thresholds and escalation contacts still refer to the intended real-world time. The repeated hour should not accidentally extend a welfare interval or create two check-ins with an ambiguous timestamp.
HSE’s good-practice guidance on shift work and handovers includes providing means of contact for lone workers and allowing adequate time for shift handovers. Test the agreed communication method and its fallback before an overnight duty, particularly if the clock change coincides with maintenance or another planned site change.
Record a proportionate verification
A practical verification record can be brief. For each relevant system or duty, note the expected time, the time shown or applied, the check completed, the result, any authorised contingency, the owner of a correction and the recheck deadline. Include the shift handover and welfare process alongside technical systems.
Keep the record proportionate and controlled. It should not become a public map of opening periods, alarm status, patrol activity or camera arrangements. Where several tenants, contractors or service providers share a site, give each responsible party only the information needed to complete its part of the check.
Update the brief when the check reveals a gap
A clock-change problem often shows that ownership was already unclear. If nobody knows who controls a schedule, who confirms the handover or who receives an escalation, correct the controlled security brief rather than relying on a one-off message for the next six months.
Review the same arrangements after replacement equipment, software updates, changes to operating hours or a move between monitoring providers. The purpose is not merely to make every clock display the same number; it is to keep decisions, records and cover aligned with the site’s intended operation.
Discuss the individual site requirement
When discussing security cover for an overnight commercial site, provide the postcode, proposed hours, intended duties, relevant handover arrangements and the authorised site contacts. Send an enquiry so the scope and feasibility can be considered for the individual premises. Do not include access codes, alarm credentials, detailed patrol information or private vulnerabilities in an initial enquiry.
Featured image: an authentic K9 Security Services archive photograph showing a black security dog with a marked security vehicle in the background at night. It is used as a general illustration and does not identify a client site or a specific deployment.