Add Banner ad start/end time setting - feature request

We fairly regularly have customers ask to have their ads start at specific times of the day. This most often occurs when they have a short, timed sale. I would therefore like to put in a feature request that the start time & stop time could be set along with the date in banner ads. I am the only one that schedules ads but it would benefit the entire sales dept. by making ads more flexible for customers. Eventually when the ad dept is trained 7 others would use it too.