Hi Cecilia,
You can try using TMVL in time Dimension.
First, select all members that have YEAR = %ACT_YEAR% into variable %FULL_YEAR% (I hope you have that Property in TIME Dimension). Then use TMVL(%FULL_YEAR%, 1). This will brings first member of next year. Finally, you can get property YEAR of that member.
Hope this idea helps.
Gersh
