On this page
01. Fix the clock02. Understand what is affected03. Options for old records04. Recalculate05. Prevent it06. A typical scenario07. Common mistakes08. Quick checklist09. Frequently asked questions
Set the terminal date and time correctly, sync it from the PC, then recalculate. Decide whether to leave the old stamps, adjust the shift rules or add approved manual corrections.
Key takeaways
- Fix the clock first.
- Do not edit raw punches blindly.
- Document the period affected.
- Check the clock after power cuts.
01Fix the clock
Follow set date and time. Also check the PC clock and time zone.
02Understand what is affected
Punches already recorded keep their wrong time. New punches will be right. Find the date you fixed it and note it.
03Options for old records
- Leave them: if the error was small or only affects non-payroll data.
- Adjust the shift: temporarily widen grace minutes for that period.
- Manual corrections: add approved records for affected days (manual punch).
04Recalculate
Run Calculate for the affected dates (Calculate) and re-issue reports.
05Prevent it
- Replace a weak backup battery.
- Use a UPS (power backup).
- Sync time monthly.
06A typical scenario
A shop found six weeks of punches stamped 25 minutes early. They fixed the clock, widened grace minutes for that period and had the manager approve the exceptions, rather than editing hundreds of punches.
Illustrative example based on common cases, not a named customer.
07Common mistakes
- Editing punches one by one.
- Not recording the fix date.
- Forgetting the PC clock.
- No UPS.
- Ignoring the battery.
08Quick checklist
- Fix terminal time
- Check PC time
- Note date
- Choose treatment
- Recalculate
- Tell HR
09Frequently asked questions
How do I know the clock is wrong?
Compare the terminal screen with your phone.
Can I shift all old punches by 20 minutes?
Some versions allow time adjustment, but check carefully and keep a backup.
Why did the date reset to 2000 or 2015?
A flat backup battery lost the clock.
Do I need to tell staff?
Yes, if it affects pay or lateness records.
This guide is part of our ZKTeco K40 and ZKBio Time.Net series. For the full start-to-finish walkthrough with screenshots, read How to Configure a ZKTeco K40 Pro with ZKBio Time.Net.
ZKTeco and ZKBio are trademarks of ZKTeco Inc. Menu names on the K40 Pro and in the software vary slightly by firmware and software version; where yours differ, look for the nearest match. Qyvea is a ZKTeco reseller and installer in Kenya.
