Field with Fiscal Week

Hello ,

Is there an easy way to create a Field that will look at a date field and determine the Fiscal Week ?  For example while setting up a FY2017 Entity that my Organization needs I need to be able to determine based on Document Date what Fiscal Week it falls into - Document Date 1/2/2017 = Fiscal Week 1.  Anyone know of an easy way to create ?

Thanks,

Linda Lockard