How to map following scenerio-Pricing

 Hi Experts,     I have following requirement,
 
       Item say 'X'=Rs 100 and the following discount is applicable to all customer
 
            1.From to To Date(01 Aug to 31 Aug)
            2.If Order limit reaches Rs.10000 @ 10%
            3.No Discount after Rs.10001

    For Ex:
       
  If a Customer first order 50 item so my cost is Rs.5000 so no discount
     and Second Order 49 Item but total is Rs.9900.Now also no discount applicable
     and third order with 25 Item now 9900+100+2400(1+24) so now order amount reaches Rs.10000 @ 10% discount applicable and after Rs.10001 there should not
  be any discount

   Here Effective date is also constraint.So please suggest me how to map this requirement.