The current ‘default’ periods for displaying trailing history graphs (Today, This Week, This Month, This Quarter, This Month) suffer from the fact that the period covered (and hence the scale and trailing information present in the graph) varies depending on where in the Day/Week/Month/Quarter/Year you are – i.e, at the beginning of the specified period there is almost no data displayed while toward the end of the period you have the full period.
Similarly if you use Yesterday/Last Week/Last Month/Last Year, the period may not be contiguous with the current time. Worst case, if you do last year near the end of this year, you are graphing a yearly period almost a year away.
Both issues could be solved by allowing for a new feature:
Trailing N HOURS/DAYS/WEEKS/MONTHS/QUARTERS/YEARS – or at least allow trailing N Days.
That way no matter when you re-run the graph, you will alway have the same length trailing period up to the current day.
Some people may want to look at 7 days, others 30 days, others a full year or any amount in between (or beyond).