Dynamic Date Selection for Background Jobs in SAP ECC 770. Support needed.

[Maston]

Hey!
Hope my message finds you well. 
I wanted to ask for support with below query. Could you please have a look into that?

Background issue description:
When I manually run T-code MB51 and select variant, the dates adjust correctly based on my dynamic date settings. However, when this report is executed as a background job, the dates remain static and do not update dynamically. In result, report is send with improper dates as system is not dynamically adjusting dates. 

My needs:
I want to understand and fix problem with static date in automatic background job (I want date area to be changed every time the job is running). 

Can you support me with that please? I am not sure, where I am doing mistake. 

Detailed information: (please feel free to ask about other information - I am trying not to get into deep details). 

1. I have setup variant in MB51 with Dynamic Date selection on field  (2 last days). 
Screenshot below:

2. I had setup Run in background job (with use of Program ->Execute in background)

Date/Time -> Period Values -> Daily -> Save

3. Review and adjust job in background with use of SM37

I had setup details related to sending background job results into specified mailbox according to below instruction:

http://scn.sap.com/docs/DOC-44263

Background job is sending results into precise email address, however it's sending all the time the same area of date (dynamic date selection is not working here). 

I am guessing the issue is not there, therefor I am not providing more details and screenshots here (let me know if I am wrong ;)).


Additional information about authorizations:
Important information: I do not have access to SA38, SE38, SM36. Just MB51 and SM37.

Can you please help me to setup Dynamic date selection for Background job?