Calling all armchair generals! Boudica's Last Stand.

[Renatus]

The main part of the battle was probably over by mid morning. Extended pursuit and rout could have lasted until the end of twilight at 20.32.

How do you like that for certainty?

Fine, except that Dio (for what he is worth) says something slightly different, I think.  He says that the armies contended for a long time and the Romans prevailed late in the day, killing many in battle by the wagons and the forest (wherever that was).  This suggests to me that the battle might not have started until the afternoon.