The following contracts are open by default:
- Until the 14th of the month, every day of the current month and of the following month. From the 15th of each month (or next working day if the 15th is a holiday), also every day of the second following month.
- The next four full-week and weekend base contracts, as well as the next two peak weekday contracts.
- The next six base and peak monthly contracts.
- The next eight quarterly base contracts and the next two four quarterly peak contracts.
- The next ten annual base contracts.
If members request so, other contracts whose delivery period is defined may be opened for registration.