ABAP HR- How to retrieve employees in past and future date

I have a requirement in which i have to retrieve employees as mentioned below:

User provides value for KEY DATE on selection screen ( I am using PNPCE selection screen).

Now, i have to retrieve employees between date range (KEY DATE- 30 days ) and ( KEY DATE + 30 days) .

example : user provides 31.10.2009 as KEY DATE on selection screen . Therefore, i have to process all employees within date range 01.10.2009 and 30.11.2009.

I am using PNPCE logical database, Can anyone tell me how to achieve this by using GET PERAS event.

Thanks in advance!

Regards,

Aleria