function to convert matlab datenum to day of year
function to convert matlab datenum to day of year

git-svn-id: https://beagle.whoi.edu/svn/ifcb/trunk@353 9f5e5bc8-6430-4f94-ad00-aad15e9f9366

Former-commit-id: fc86695e5930ced464867287866ca1372a0d990d
hsosik/ifcb-analysis,hsosik/ifcb-analysis,hsosik/ifcb-analysis,hsosik/ifcb-analysis,hsosik/ifcb-analysis