Feature suggestion: Avoid misleading drops at the end of each period by adjusting the date period to exclude unfinished periods.
For example, if we are in the middle of the week, either stop the graph at the prior week OR change the dates for all weeks to have complete weeks. So if I check on a Thursday, the graph shows Thurs-Wed weeks instead of the default. If I check the daily numbers, by default the day ends YESTERDAY.
This would provide a more realistic view as you wouldn’t always have that terrible drop for the current period (esp in the morning). And people could always override.
What you’re suggesting would require a whole other set of options in the control panel to “Exclude Today”, basically. Personally, I prefer to see “Today”, so I can see how this day is stacking up against the other days (or week or whatever), even if it’s not done yet. And an option like that may confuse people, but I’m not sure. It’s a viable suggestion though, at least for all of the views except for “Day” (since you can already default the view to be “Yesterday” not "Today).
Edit: What would also be nice is if Piwik could “guess” what the value was going to be based on the averages from the rest of the graph (Excluding zero-values); this would also solve the “incomplete for today” graph problem. Perhaps a dotted-line on the graph for a possible “projected traffic” page? Or something along those lines? I know it’s possible to get a “best fit line” from a set of points that can be used to estimate the value of “future dots” (for lack of a better term), it would be cool if Piwik couild do that.