Calendar month and year from date in HANA

Hi,

I created analytical view on the sales table VBAP and vbak.

Following are my requirements

1. I have a created date in vbak and I need to derive Calendar month and calendar year from the date..How can i do that in HANA??

2. I have actual delivery date and GR dates in the purchasing tables. Now i need to  calculate the days difference in HANA. I tried daysbetween function but its not working.

3. After looking at the raw data in data preview. Is it possible to remove columns. I mean slice and dice?

Thanks
Sri