How to set up a dynamic Default value of Parameter in Paginated Reports

[Emilyyying]

Hi, Can anyone tell me how to set up a default value of a page parameter which is the latest Date/Time in the list? So that, when I run this report, it will automatically select the newest time in the parameter list and show the result.

Another question, how can I remove the "All" option in the parameter list (at the bottom of the list)?

     

[Emilyyying]

Can someone help me with this question?