formating date labels

[User (Legacy)]

When creating ActiveX chart where Axis X has date as labels I would like to 

display the labels in format: MMM-YY 

This is working fine when I use: 

chart.DateFormat = "DMMM-yy" 

but when I go with the mouse over the chart that is also all I get. 

What I would like to achieve is following: 

on the X axis I want the format MMM-YY 

when going over the graph itself with the mouse I would like DD-MMM-YY 

format 

How can I achieve this. 

Thanks in advance for your help 

Filip