Time spent stat suggestion, productivity grouped by hour throughout the day

Right now the Time Spent chart is a simple bar graph listing how long we've spent at the computer each day. Wouldn't it be better if we could have a stacked bar graph that showed how much time we spent on each activity during each hour?

Another stat suggestion would be a clustered bar graph that showed how much time we spent on each activity (or productivity / efficiency numbers) that could be aggregated over multiple time periods. That way we could see if we were more productive early morning, afternoon, or late night.

Edit: I just realized this feature already exists but is limited to two tags. Could you make this automatic to all tags?