Calculation Function equivalent to MDX ".lastchild"

@CHILDREN(

Hi all,

In a calc script i have to check if the current lvl 0 member of the time dimension is the last month of a quarter.

Hierachy of time dimension: Time -  Year - Quarter - Month

In mdx i would do it like this  : 

IIF(IS([Time].CurrentMember, [Time].CurrentMember.Parent.LastChild),

In the calculation script i can only say   

@CHILDREN(@PARENT (Time))

There is no "first" or "last" child possibility

I have no idea how to check this.

One thought was to use  "@NEXTSIBLING(Time)". When the current member is the last month of a quarter this function will return an empty string.