Some of the Charts icons have a clock symbol on them. What does this mean?

Some of the Charts icons have a clock symbol on them. What does this mean?

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.