Creating chart problem

I have a changing data series, and at one time, for 6 months I had a chart showing the changes. Then suddenly the chart stopped working. I have retried to create the chart, and it appears to be okay, but the dates should be from 7/23/13 to 6/3/14. Unfortunately the Axis wt the dates has only three #'s, and these do not appear to be dates at all. The numbers are 40122, 40200, & 40284? The representation of the graph appears to be okay. The only other problem I have wt the graph, is how can the graph appear to fill up the whole graph area. It is very condensed and not very long. I think the reason is because I choose the entire A-G axis. Still if I hadn’t I didn’t know how I could show how the data changing over time. I’m quite sure there is a way, since I had it correctly do this about 6 months ago. That was before a libre office update. Thank you …

The numbers 40122, 40200, & 40284 are the dates Nov 5, 2009, Jan 22, 2010, & Apr 16, 2010. When you double click on the chart and double click on the x-axis, the format window appears. Go to the Numbers tab and toggle the Source Format checkbox. If it is unselected, you can change the format of the number to anything you want.

To set the range for the dates, go to the Scale tab, select Date for the Type. The maximum and minimum values appear and you can then set them to the range you want.