When do Daphne and Niles start dating?

Daphne and Niles start dating in the finale of "Frasier," specifically in Season 11, Episode 24, titled "Goodnight, Seattle." Throughout the series, Niles harbors a long-standing crush on Daphne, and their relationship finally evolves into a romantic one in the final moments of the show. After years of longing and comedic tension, they share a kiss, marking the beginning of their relationship.