I think the equivalent for the majority of Australians really is Christmas. Americans tend to see extended family on Thanksgiving, whereas Christmas (for those who observe it) tends to be a smaller affair more likely to be spent with immediate family only. By contrast, Australians are much more likely to see extended family at Christmas. Also, our traditional equivalent to the Black Friday sales is the Boxing Day sales, which is another way in which Australian Christmas = American Thanksgiving. Very many secular Australians celebrate Christmas in a completely secular way, with no religious component.
Of course it is not entirely equivalent, in that Thanksgiving is a more religiously inclusive holiday than Christmas is. While there are people with a religious objection to both, there are many more with a religious objection to the later but not the former.
Day after Thanksgiving when stores reopen having been closed the day before. Traditionally called “Black Friday” because it put retail businesses books back into the black.
I think this recent adoption of Black Friday in Australia is dumb, for two reasons:
(1) It makes zero sense given we don’t celebrate Thanksgiving
(2) Given the term’s historical association in Australian culture with mass death (1939 Black Friday bushfires that killed over 70 people, 2009 Black Saturday bushfires that killed over 170 people), using it for sales could be seen as disrespectful and culturally insensitive
Of course it is not entirely equivalent, in that Thanksgiving is a more religiously inclusive holiday than Christmas is. While there are people with a religious objection to both, there are many more with a religious objection to the later but not the former.