TTLock Time Sync Problem: Fixing Clock Drift and Expired Codes

Time-based passcodes — timed, one-time, and cyclic (recurring schedule) codes — are validated against the clock inside the lock itself, not against your phone's clock. If that internal clock drifts or resets, a code that should still be valid gets rejected, or a code that should have expired keeps working.

• Battery change reset the clock. Removing batteries for more than a few seconds on some models causes the internal clock to reset to a default time or stop entirely until it's re-synced.
• The lock has sat disconnected for a long time. Without a Bluetooth connection or gateway, the lock's clock can drift gradually from real time, especially on cheaper crystal oscillators.
• The admin phone's time zone is wrong. Because sync pushes the connecting phone's local time to the lock, a phone with an incorrect date, time, or time zone setting will sync the lock to the wrong time too.
• No gateway is installed. Locks with a gateway resync automatically at intervals; locks that only ever connect over Bluetooth only resync when someone opens the app nearby.

1. Check your phone's date, time, and time zone. Set these to automatic/network-provided time before syncing, since the phone is the source of truth the lock copies from.
2. Connect to the lock over Bluetooth as the admin. Open the app, tap into the lock, and let it establish a connection — this typically triggers an automatic time sync in the background.
3. Wait for the sync to complete before testing codes. Give it a few seconds after connecting; test a timed or cyclic passcode only after the app shows the lock as connected and idle again.
4. Re-issue any codes that failed during the drift window. If a timed passcode expired early or was rejected, delete and recreate it after the clock is correct rather than trying to reuse the same code.
5. Install or reconnect a gateway if drift keeps recurring. A gateway checks in with the lock periodically and keeps its clock aligned without anyone needing to open the app in person.

Not every access method depends on the lock's clock. Permanent passcodes, cards, and fingerprints check identity only and are unaffected by time drift. Time-sensitive codes are the ones that break:

• One-time passcodes. Valid for a single use within a set window; a drifted clock can make the window appear to have already passed.
• Timed passcodes. Valid only between a start and end date/time; drift shifts that window relative to real time.
• Cyclic passcodes. Valid only on certain days or hours each week (e.g. office hours); drift can make them refuse entry during what should be an active period, or allow entry outside it.

• Still drifting after a sync? Some locks lose meaningful time between connections if the internal clock hardware itself is failing; this is more common on older units and usually needs a service check rather than another sync.
• Gateway installed but drift persists? Confirm the gateway itself is online — a gateway that has dropped off Wi-Fi can't keep the lock's clock aligned even though it looks paired in the app.
• Codes still rejected after sync? Rule out a separate passcode issue (typos, wrong code type, or the passcode limit being reached) using the passcode troubleshooting guide.
• Smart Lukko is an independent third-party app for TTLock-compatible locks, not affiliated with TTLock or Sciener, and clock drift tolerance varies between hardware models.