> For the complete documentation index, see [llms.txt](https://docs.nexthink.com/platform/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nexthink.com/platform/references/references-classic/search-and-information-display-classic/engine-data-history-classic.md).
# Engine data history (classic)
Nexthink Portal provides an administration page so you can check the current state of data history on each connected Engine. You can access this feature by clicking on the gear icon in the main navigation bar and then selecting the **Engines** administration dashboard.
All the Engine instances associated with Portal are listed in a table view and the system automatically retrieves the following information from the connected ones:
* **First event**
The date and time of the very first event stored in the Engine database.
* **Last event**
The date and time of the last event recorded in the Engine database.
* **Available data**
The elapsed time between the first and the last event, reported in days.
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