MD61 Demand management entries and MRP Scheduling

Dear Gurus
I've done relatively all the settings regarding MRP and scheduling. Now when I put a single value 10,000 in MD61 for a month, system breaks the quantity in 20 planned order of 500 because I've set the batch size as fixed at 500 quantity. But system places all the orders on the first day of the month. It's not auto scheduling and distributing 20 planned orders along the whole month.
How can this be achieved?
I don't want to break values and put them on a day basis in MD61/MD62 (demand management)

Regards,
Shankar