To Update Maintenance Licensing dates:

 

1 - Open the PowerOLAP Server Control as an Admin (Right-click on the program and select run as Admin).

2 – Click on the server under Servers in the Left-side box. This will allow you to click on the Options in the Ribbon.  

3 - If license is still not updated in PO Server > stop and start the PowerOLAP Service.

4 - Re-check licensing again by performing step 2.