When a Job is defined, right-click on the Job or Task in the Server/Job/Task grid and select Job log to open the log window.
The data in this window is based on the local database file. The number of entries in this file is limited by settings in the Server settings->Log->Database settings.
The dates you see is the From and To date. These are the minimum and maximum values from the local database.
The Job log provides optional realtime update of execution history. The Tasks within the Job will show up while executing.
Filter
You are able to filter between successful and failed Jobs.