The filename does not appear to be associated with a widely known viral video, ARG (Alternate Reality Game), or specific public blog post.
In many technical or security contexts, a filename like this often represents a (e.g., footage captured between midnight and 6:00 AM). Because the "mkv" format is a common container for high-definition video, it is frequently used by security systems, screen recorders, or media preservationists. 0000-0600.mkv
If you are referring to a specific creepypasta, mystery, or a file found in a particular online community, could you provide more of what happens in the video? Finding the right details will help me track down the exact story or "lore" you're looking for. The filename does not appear to be associated