Some chart types are produced twice, this is indicated by the use of the same number and the introduction of a clock symbol to differentiate them (see image below)
When present this indicates the existence of a single chart that spans the start and end time chosen by the user and a daily 24 hour chart that span the same overall period of time. For example...
Supply side Chart 2 is the 'System power and output' chart...
Supply side Chart 2 with a clock symbol is the daily version of the same chart...
The additional filter permits the user to review daily charts for the same chart type.