I Googled it and came up with this:DatedBrent is a benchmark...

I Googled it and came up with this:

DatedBrent is a benchmark assessment by S&P Global Commodity Insights of the price of physical, light North Sea crude oil. The term "Dated Brent" refers to physical cargoes of crude oil in the North Sea that have been assigned specific delivery dates.

and this

How we assess Dated Brent

We assess the price for dated crude streams in the North Sea - Brent Ninian Blend (from which Dated Brent takes its name), Forties Blend, Oseberg and Ekofisk. Taken together, these four crudes represent a robust supply of approximately 1 million oil barrels per day of production.

The most competitive grade of crude defines the final printed price of our Dated Brent assessment each day.

Our Dated Brent price assessment reflects the tradable, repeatable spot market value of the most competitive grade at 16:30.00 London time precisely.

We publish bids, offers, expressions of interest to trade, and confirmed trades during our Market on Close assessment process every day. This information is summarised in our daily newsletters and is published in full on our real-time information service, Platts Global Alert.

So . . it looks like a daily average.
I'll keep looking to see if the actual figure is available to us ordinary guys.