Diazepam (Valium) half life is 1-2 days. Its active metabolites in the body are: desmethyldiazepam, methyloxazepam,oxazepam, temazepam.
Ativan is lorazepam and half life is 12-16 hours. No active metabolites are demonstrated for this drug. Most of it gets excreted as inactive glucuronide ativan.
Xanax, alprazolam is also about 12-16 hours. It produces 2 main metabolites: a-hydroxy alprazolam and a benzophene derivative. The listed bio activity of a-hydroxy is half that of alprazolam and the benzophene derivative is essentially inactive. Their half-lives appear to be about th same as alprazolam.