vBulletin Manual - Scheduled Task Log

The scheduled task log is simply a way to see when tasks are run and what effect they had. When you go to Scheduled Tasks > Scheduled Task Log, you will be presented with a screen similar to this:

Here, you may view previous log entries or prune old entries.

To view log entries, select the criteria you want and click [View]. This will lead you to a screen that looks like this:

ID – ID number used to identify the log entry.
Action – title of the scheduled task run.
Date – date and time that the task was run.
Info – information returned from the task. For some scripts, this information may include users affected.