What You Can

Point of Sale -> Discounts

Date period for discount.
Activete / Deactivate
Discount for All Customer or for selected.
Discount Type: Simple Discount, Buy X for the procs of Y, Buy X for Fixed price Y
Dicount for: All Products, Product Categories, Specific Products, Specific Categories
Value Method: Percentage off

Point Of Sale -> Configuration -> Point of Sale.

Set Discount Journal.

Accounting/Invoicing -> Adviser - > Journal Entries.

Install Accounting and Finances.
Look in Discount Journal.
When You Click in Point and Sale "Validate Closing and Post Entries" Discount Subtotal - write record in Discount Journal

More Example

Most of times the discounts will simply add up. So if the drink code 601 is included in 3 different discounts, the it's going to get all of them together

- List price of product 601 = US$10
- Christmas Discount = 5% = US$0.5
- Thanksgiving Discount: 6% = US$0.6
- Hanukka Discount: 2%=US$0.2
- All discounts == US$1.3
- Final Price =US$8.7

However, discounts can be also exclusive. For example, I can create a "2x1" discount for the product 601. Basically the second 601 will be free

- List Price = 2 x US10 = US$20
- 2 x 1 Discount = 50% = US$10
- Final Price = US$10.
But on top of that US$10 discount, I could NOT want to apply the other discounts (which will be another US$2.6 (13% of US$20). If the buyer buy just 1 of 601 then she will get the 13%, if she buy 2 then she get the 2 x 1 discount.