I though it would be interesting for us to have this technique (or post) at chandoo.org. What I was thinking was would it be possible to have at line graph moving automatically (something similar to google spreadsheets). So we can have our normal scroll bar for manual range selection and if we want to (maybe for presentation purpose) we can enable an automatic update button and graph's trendline will keep on looping based on the date range. You guys have done it before ? I am pretty sure we can achieve it in excel. Looking forward to hear interesting reply from you guys, Cheers !