I did a googling and I've found, in a Brazilian site, a rumor that Steam Halloween Sale will begin this 28th October. The link for the site is (in Portuguese):
https://jovemnerd.com.br/nerdnews/halloween-sale-do-steam-comeca-em-28-de-outubro-rumor/
The Brazilian article points to a Reddit link, where a Russian developer leaked the info:
Reddit
Steam ordinary promos (weeklongs, midweeks, weekends and daily deals) usually begin here in Brazil at 2 p.m local time. I'm writing here at 4 p.m now, and maybe that's why I can't see weeklong deals for this week. Maybe Steam is just saving promos for the next 28th Oct.
https://jovemnerd.com.br/nerdnews/halloween-sale-do-steam-comeca-em-28-de-outubro-rumor/
The Brazilian article points to a Reddit link, where a Russian developer leaked the info:
Steam ordinary promos (weeklongs, midweeks, weekends and daily deals) usually begin here in Brazil at 2 p.m local time. I'm writing here at 4 p.m now, and maybe that's why I can't see weeklong deals for this week. Maybe Steam is just saving promos for the next 28th Oct.