Enhancement Request (for your consideration only). It would be really nice to have an extra attribute in a person delegation settings - delegation end date/time. Usually when you make delegation active, you already know when this delegation should expire (returning from business trip, vacation ending, etc.). So it would be nice if you might be able to set date (& time probably) when the delagation should be set inactive automatically. vFire polling service may periodically check every active delegation and set it as inactive when the specified end time comes.