Depreciation for specific scenario

What is the guide lines for the below mentioned scenario:

1. Asset Life : 5 years and 0 months totaling to 60 months

2. Per year depreciation portion should be divided into 9 months instead of 12 monther per year.

3. the depreciating months are from Jan to Jun and Oct-Dec. The  non depreciating months are from Jul to Sep for which there should be no depreciation.

Eg:

Asset Cost: 60000

Per year depreciation: 12000

Normal Depr: Per month from Jan to Dec (12months) :1000 which is 12000/12

need as: Per month from Jan to Jun and Oct to Dec (9months): 1333.33 which is 12000/9. no depreciation for Jul, Aug and Sep.