Online material decays in ways that make this distinction matter. A post's platform-visible timestamp can be edited, ambiguous across time zones, or simply absent by the time anyone captures it. Capture time, discovery time, platform-visible time, and review time are four different events, and conflating them is one of the most common weaknesses in self-collected evidence. A careful record keeps them as separate fields: when the material was found, when it was captured, what time the platform displayed, and when a reviewer examined it.
UTC is the preferred format for cross-platform matters, since it removes ambiguity when material spans time zones or when a matter later needs to be reconstructed by someone unfamiliar with the original collector's local time. The timestamp's value comes from what it is attached to: the source URL, the capture method, and the custody record. A date on its own, without those attachments, is closer to a claim than a record.
Finium records capture time, source-visible time (where shown), discovery time, and review time as distinct fields in every evidence file, linked to the same evidence ID as the underlying capture, so a reviewer can see the full sequence rather than one blended date.