On Qingming Festival, the whole family pays respects to the ancestors.
Tips
culture
Almost always in 祭祀 (to offer sacrifice, to perform rites). In ancient texts 祀 could also mean a year, since the Shang dynasty counted years by the round of seasonal sacrifices.
Left ritual radical, the side-form of 示, which depicts an altar. It marks 祀 as belonging to worship and the spirit world. Same ritual family as 祭 and 神.
Right 巳 supplies the sound — sì with no tone shift. It contributes no meaning here; it is one of the twelve earthly branches, used purely for its reading.