Google has officially rolled out ad scheduling, or "dayparting" for Adwords. Now advertisers can automatically adjust their bids, pause and restart their campaigns based on the time of day or day of the week.
If your target audience spikes in the evening, you can set your campaign to run beginning at 7 p.m. and ending at 10 p.m. You can set it for weekdays or only weekends.
This feature has long been anticipated. It's going to allow advertisers to experiment and fine tune their campaigns to maximize their ROI. I can hear the Hallelujah's from here.