Hi Naresh,
In SAP HANA SQL, to the best of my knowledge there is no support for shifting start day of week (default being start Monday (0) thru Sunday (6)). However you can create a UDF user defined function to incorporate logic of start day shift and use the function in your SQL.
Another option I can think of is if Sunday is always start day of the week for your requirements, you can generate time data at week granularity with start day as Sunday
I think best option would be to create a UDF with the start date shift logic and use the function.
Link on UDF:
~Gopal