Was the Pleiades used to denote the winter sailing period in the ancient Mediterranean?

I've seen a few references to the setting of the Pleiades being used to denote the winter sailing season in the ancient Mediterranean. This shows up in a few dictionaries, and in 'Mare Clausum? Sailing Seasons in the Mediterranean in Early Antiquity' (Mediterranean Historical Review, 2005) Oded Tammuz quotes some ancient scholars as recording that the 'winter season [begins] with the setting of the Pleiades'.

This makes perfect sense, but I've always known the Pleiades as winter stars. They're visible in winter, not summer. The winter ends with the setting of the Pleiades, not starts.

What am I not understanding about ancient sailing times? Or what am I not understanding about ancient astronomy?