@dave. You're right. Must be a mistake!
"On average, your frost-free growing season starts Jan 3 and ends Jan 30, totalling 27 days. You will find both Spring and Fall planting guides on this page."
Thank you for this report. For climates such as yours, our calendar is supposed to give a message about where to find information on vegetable gardening, rather than try to give dates and so forth. I've updated the calendar.
