"grandfathers, eldfathers", sometimes translated as Forefathers' Eve) is a term in Slavic folklore for the spirits of the ancestors and a collection of pre-Christian rites, rituals and customs that were dedicated to them.

The name "dziady" was used in particular dialects mainly in Belarus, Poland, Polesia, Russia, and Ukraine (sometimes also in border areas, e.g. Podlachia, Smoleńsk Oblast, Aukštaitija), but under different other names (pomynky, przewody, radonitsa, zaduszki) there were very similar ritual practices, common among Slavs and Balts, and also in many European and even non-European cultures.

"domestic deities, souls of the ancestors, guardian spirits of the house", Ukrainian didko "chort, devil, impure/evil power" or Proto-Slavic *dědъkъ: Lower Sorbian źědki (pl.)

The basic ritual form was feeding and watering of souls (e.g. honey, groats, eggs, forge and vodka) during special feasts prepared in houses or cemeteries (directly on graves).

A characteristic feature of these feasts was that the people who ate them dropped or poured some of their food and drinks on the table, floor or grave for the souls of the deceased.

[6] In some regions of Poland, e.g. Podhale, in the place of someone's violent death, every passer-by was obliged to throw a sprig at the stake, which was then burned every year.

Therefore, people asked them to pray for the souls of their deceased ancestors, offering food (sometimes special ritual bread prepared for the occasion) or cash donations in return.

To this day, in some regions of eastern Poland, Belarus, Ukraine and part of Russia, it is cultivated to carry on the graves of the dead a symbolic meal in clay pots.

[10][11] Every year in Krakow, a traditional Rękawka [pl] is held, directly related to the ancient custom of spring ancestors' holiday.

A different strategy was adopted in the Uniate Church, which obliged the priests to go with the rural population to their dziady and pray the Angelus, the Hail Mary and other christian prayers.

[15] In some regions, the Uniate priests celebrated special processions at the cemeteries, during which they consecrated individual graves and collected food and money left on them.