"The Obscurial was here? Where did she go?"
-- Percival Graves
Five Aurors attempt to capture Gellert Grindelwald at his remote, derelict chateau, possibly somewhere in Switzerland. The five approach the chateau only to be blasted by a “sudden explosion of pure white light” that throws them back and appears to have killed them. From this confrontation, Grindelwald travels to the United States of America to track down an Obscurial which he saw in a vision. Once there he impersonates Percival Graves, one of the most powerful Aurors in MACUSA, and tries to find out who the Obscurial is.
The date of November 28, 1926, was on the newspaper seen in the film just after the attack. The headline read "GELLERT GRINDELWALD Dark Wizard Strikes Again in Europe." Since the attack happened at night, we are assuming that this newspaper story appeared the next day. Of course, since this newspaper is a prop created by MinaLima and not written specifically by Rowling, the date is at best an approximation. Rowling's script doesn't list a date. It does, however, state the that next scene with the ship gliding into New York harbor happens the next morning, and newspapers seen in the main lobby at MACUSA headquarters that day say are dated December 6th.
Why do we state that the Chateau is probably located in Switzerland? We're making a little bit of an assumption here, but one with some pretty solid canon to back it up (WFT, scene 60):
An impressive hall arranged like an old parliament debating chamber. Every seat is occupied by wizards from all parts of the world. MADAM PICQUERY is presiding, GRAVES at her side.
The Swiss delegate is speaking.
HEINRICH EBERSTADT: . . . that threatens to expose us all.
MADAM PICQUERY: I will not be lectured by the man who let Gellert Grindelwald slip through his fingers—
Rowling is writing a script here, not relating actual historical events. It is highly likely in that context that Rowling is having Picquery refer to what has already happened in the script rather than bringing up random, non-existent events. Therefore we say that the confrontation at the chateau is very likely the event where the Swiss let Grindelwald "slip through" their fingers, and therefore likely that the chateau is in Switzerland.