[Q] How to set my "next holliday" in google now?

Hi
in google now, in the weather settings, theres a checkbox with "next hollidays" or something.
i'm leaving for canada tomorrow, so how can i tell google this? i'd like the meteo, but the only way i find is to set my home as montreal (which is not).
this "next holliday" checkbox, has to be there for a reason. how to use it?
same goes for "flights"... how can google know what flight i'm taking?

thanks a lot !