> For the complete documentation index, see [llms.txt](https://docs.tryterra.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.tryterra.co/help-center/help-topics/no-data/delivery-delays-lag/zepp-amazfit-sync-delay.md).

# Why does Zepp or Amazfit data arrive late or with low step totals?

Zepp data reaches Terra only after the watch has synced it to Zepp, and Terra then picks it up on its next check.

**Zepp data reaches Terra only after the watch has synced it to Zepp, and Terra then picks it up on its next check, about every 15 minutes.** Zepp does not notify Terra of new data, and a watch can sync a workout days after it happened, so a session can reach you the next day or later.

* Amazfit watches sync through the Zepp app, so connect Amazfit users with `ZEPP`.
* Each check also looks back over the last few days, so data that syncs late is still picked up.
* A day's step total reflects what Zepp held when Terra last checked. If more steps sync for that day later, the day is sent again with the new total, so overwrite daily records by user and date rather than keeping the first one.

If a day still looks low well after the user's watch has synced to the Zepp app, report the user ID and date for investigation.