Three hours on three? What does it mean?
Context:
‘And on Samain Eve,’ I said, ‘you light the fires and wait?’
‘Three hours on three, Lord, the fires must burn, and at the sixth hour we begin the ceremony.’ And sometime after that the night would turn to day, the sky would fill with fire and the smoky air would be lashed into turmoil by the Gods’ beating wings.
Question:
Three hours on three? What does it mean?