I'm really glad to have family members able to do pig slaughter even nowadays. It is a great experience and great event we have twice a year.
The slaughter (Zabijačka) in Czech Republic traditionally takes place in the autumn and early winter, and the timing has several practical considerations. It can start as soon as it gets cold, as the cold is required as a natural method of preserving the relatively large quantities of meat during the butchering. Yet, because people often do the work in the open, it is preferable that the temperatures aren't too much below freezing during this time, hence the slaughter rarely extends into winter. Also, slaughter activities typically need to produce results before the Christmas season, to provide for the festive cuisine.
I did some photos at our last pig slaughter 2 months ago, so you can see how is pig slaughter in our country. All photos are taken with my Leica M7 and Ilford BW film.