You can use automated rules to raise and decrease bids based on day of week, or even based on hour of day.
For example, you can set up two daily rules to increase your bids between 6:00 PM and 10:00 PM every evening. The first rule would increase your bid by 25% at approximately 6:00 PM and the second rule would decrease the bid by 20% at approximately 10:00 PM, thus bringing it back to the original value ($1 increased by 25% is $1.25, $1.25 decreased by 20% is $1 again).
Let's set this up!
First task will increased the bid sometime between 6:00 PM and 7:00 PM. If you want to use exact time (e.g. 6:00 PM sharp) you can set this up using schedule. But then you'll have to create two separate rules—one for increase and the other for decrease.
Now the second task will decrease the bid by 20% sometime between 10:00 PM and 11:00 PM
Here's a handy way to calculate increase and decrease %. Given an increase of x %, the corresponding decrease d % to get back to the original value follows this formula: d = (100 * x) / (100 + x). In the above example, x = 25. Then d = (100 * 25) / (100 + 25) = 20.