Initial Stock Upload with Age

Hi SAP Experts,

Greetings to all...
I wish to ask following question:
I wanted to upload the initial stock using MB1C and movement type 561. I have created a LSMW for this. I wanted to save the age of the stock. For aging I have specified the Document Date as date at which the GR was performed and Posting Date as current date. But after the upload when i see the material document that is posted - the Posting and Document date is shown as current date.

So i wanted to ask
Is there any other field we should consider for saving the AGE of stock or there is some problem with my lsmw?

Thanking you in advance

Regards,
UK.