X-axis time format setting issue with quality control chart

Hi Experts,

Recently I am confused by the reference axis(x-axis) setting in quality control chart, would anyone give me a hand on this?

The issue is as below,

I am using standard control chart type '515' in sampling procedure, which has 'time of creation' setting for reference axis (x-axis). When I record results for such characteristic, the control chart can be generated well, but the time showed in x-axis is not as I expected, for example, I just want to show one year's data; so I changed the fomart of x-axis by changing the Minimun, Maximum, Major Unit and so on, and then apply it, then the x-axis can show as expected, but when I save it and call up the chart again, the data showed in x-axis totally messed(not as expected).

Can anyone please give me an explaination on this happening?

Many thanks.

Benny