Werk #20220: filestats: Handle file modification times from the future

Component	Checks & agents
Title	filestats: Handle file modification times from the future
Date	Jul 10, 2026
Level	Trivial Change
Class	Bug Fix
Compatibility	Compatible - no manual interaction needed
Checkmk versions & editions	3.0.0b1 Not yet released Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT 2.5.0p10 Not yet released Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT 2.4.0p35 Not yet released Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

Previously, the check plug-ins "File group" and "File" would crash when a monitored file reported a modification time in the future, with a message:

raise ValueError("Cannot render negative timespan")

This can happen when the files reside on a system whose clock is ahead, on a network share, or on removable media, or when a file was explicitly stamped with a future timestamp.

Now, the affected service goes to state UNKNOWN and reports the following message:

The timestamp of the file is in the future. Please investigate your host times

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