I found this on the ReservationKey blogspot:
Rate Adjustment Shows in Room Listing Price
If your room/unit price is being adjusted downward by a Rate Adjustment, we are now showing the original price, plus the Adjustment name, and then the adjusted price. This is a good way to let your guests know they are getting a discount.
Since Rate Adjustments can also be used to increase prices, we are making sure only to show this section when the price is decreased. We have added ID's to both the original price section and the discount name, so the look and feel of both can be adjusted with CSS in your theme (or hidden if you don't want to use this feature). The tag information is:
#span_originalprice {text-decoration: line-through;}
#span_rateadjustmentname {color:red;font-weight:bold;}
Select Days of the Week For Discount Codes
You can now select which days of the week a discount code can be used. This makes it now possible to use discount codes to run specials such as "Stay 2 nights or more during the week and receive a $100 discount." By setting the code validity to only Sunday through Thursday, the user will see an error message if they try to use the code on other days of the week. If no days of the week are selected, then the discount code is valid for all days.
For your 2-night minimum problem:
1. Go to the Properties tab
2. Select Rate Adjustment
3. Select Add Rate Adjustment
4. Give your Rate Adjustment a name
5. Enter the date range, i.e. if you want the whole year, select January 1 - Dec 31
6. Click on the box(es) for the days where you want the rate to be applied, in your case Friday and Saturday.
7. If the rate is not changing, set the "Adjustment" to increase by 0.
7. Change "Minimum Stay" to "2"
8. You can select if you want to allow a reservation to be made if you're one day into the two-day minimum, but still have an opening. This acts as an override in case you have an one open night that was not filled for any reason.
9. The "Ignore Rate Rules" selection allows you to choose whether or not you will allow other discounts to be applied during this rate adjustment period.