How do I change which days count as weekend nights?

To change which days count as weekend nights, open the Pricing section of your listing and tick or untick the day buttons, then click Save Weekend Price. The setting lives under Manage Listings > Edit > Pricing > Rates & Fees, in the Base Price block: look for Charge more for weekend nights? with the day toggles TH, FR, SA and SU beside it, and the weekend rate in the box to their left. To charge the weekend rate on Friday and Saturday only, tick FR and SA and untick TH and SU.

To turn weekend pricing off completely, use the Weekend Pricing switch in your calendar settings under Base Pricing - it saves as soon as you click it. You cannot switch it off from the Pricing page, and unticking all four days there will be refused.