2011 CFAI AM Time Horizon Q person, couple, change, 2011

Iginla2011

So my understanding of this is that there is a change any time there is change in their circumstances/cash flows.
Now the couple are retiring next year. Should the time horizon not factor that in? So you should have a three stage horizon. from now till retirement then until one of them passes away and then the life of the last person. However the answer just specify it as two stage.
WHat are your thoughts?

Nishant1

The answer key says that an alternative answer is to have a three year time horizon, with the first stage being up until their large liquidity need.  That need occurs next year, at retirement.  So both answers would be accepted.