Unable to change Category Axis date format in launch pad (BI 4.1 SP4)

We are unable to change category (x) axis datetime format in BI Launch Pad. I can set it via assign data (attachment) but the change has no

effect: nothing is changed. The format seems to be stuck to default date format. I want to see e.g. hours and minutes. This works

fine in Rich Client but not in BI Launch Pad using HTML format. We don't use Java (Applet) format and I did not test this with

Java. I tried with Chrome 38, Firefox 28 and IE 10.

We are facing this issue in BI 4.1 SP4 version.

Please suggest me if this is normal behavior and any document is available for this.

Thanks

Prasad