Calculations of the volume-weighted average prices of the time slice 00_04 do not take account any time changeover, as this ensures the direct comparability of data in the files comprising offers.

However, volume-weighted average prices determined across all six time slices in a day are standardised for a time slice of 4 hours, as this makes it easier to compare them with the volume-weighted average prices of individual time slices. Accordingly, if the time slice 00_04 only comprises three hours, all offers accepted during the time slice in question are processed when calculating average daily prices as if the capacity price offered had been 33 percent higher and for a time slice lasting 4 hours. Similarly, for a time slice of 5 hours' duration, all prices per unit are lowered by 20 percent and the offers processed as if they had applied to a time slice lasting 4 hours.

The marginal capacity prices across all six time slices of any one day are calculated as the maximum across the marginal capacity of all six time slices. No separate consideration is given to clocks going forward and backward at the beginning and end of summer time respectively.