I am trying to create a graph that will automatically update itself based on
todays date. For instance i would like to graph data from the past 28 days
only starting from todays date. however every day i have to go into the
chart and reselect the source data because it is constantly changing on a day
to day basis. Is there a way to do automatically update this. or a formula
that i can put into the source data using todays date?