Season 2 Episode 5
Episode aired october 24, 2000
darla tries to drive angel over the edge in hopes of getting him to embrace his dark side.
cordelia says that angel is 248; he corrects her to 247. this indicates that angel is counting from the day he was sired (and not including the hundred years spent in acathla's hell dimension), in 1753 (he was already 26 years old at the time).