The Day-Ahead Market refers to electricity purchase and sale transactions with a physical delivery obligation on D-day.

In the Day-Ahead (DAM) Market, electricity is traded in both OTC (Over the Counter) bilateral contracts and power swaps. Transactions for the purchase or sale of electricity with a physical obligation to deliver on day (D), are auctioned on day D-1, where all transactions of energy derivative products with physical delivery for each Market Time Unit of the of Physical Delivery Fulfillment Day are declared. Participation is mandatory for producers, while it is optional for all other participants. Producers are obliged to submit sell orders for the available capacity of their units, which have not yet been allocated through energy financial products transactions or other transactions involving wholesale energy products with a physical delivery obligation. The Day-Ahead Market operates in real time. At the end of the day (closing time), each market must be balanced in the sense that planned production must equal forecast demand plus/minus net exports to or imports from other market zones. In the DAM market, market zones can be combined with each other. The main benefits of a Day-Ahead market are, among others, that it increases the reliability of the system by providing sufficient warning for planning, reduces the impact of uncertainty on real-time market prices, and increases liquidity as trades can be financial contracts rather than contracts for physical delivery.

In the Day-Ahead Market, the quantities of energy as derived from the bilateral contracts and the Forward Market of HENEX for the products with a physical delivery obligation are also declared.