I have a very large database which contains temperatures every three hours for the duration of a fire season in Australia. I wish to display a chart of the previous week's data and not the older data. The chart will display the temperatures, relative humidity, wind speeds, fire danger ratings for forest and on grass on the y axis. I would also like to limit the data to the maximums for each day. However, i don't seem to be able to set the filter for the X axis using a calculation. Can anyone help me?