Hi Martin,

It is because usually partir is associated with holidays.

If someone says to you -

Où tu vas ? = Where are you going?

they will mean now. 

In the example, the fact that 'this year' was added is clearly talking about holidays.

Hope this helps? 

Bonjour Martin,

Partir = to go (to go to a place) / to leave (to leave a place)

 

 

 

I hope this is useful.

Bonne journée !