V-lookup & H-lookup combo: find the day

Hi guys,

I'm looking for a formula in "planning"K8 and O8 that looks up the 1st day and the last day of the week (H8) in the year (D8). All the years, weeks and dates are in "Data".
Also: I don't see why the "year" listing has an empty space in it :S

Thanks in advance!
Happy holidays!

Weekplanning Spanjeberg.xlsx