How to prevent customers from booking at the last minute?

General setting

Go to HBook > Misc > Opening dates. You can set a number of days from current dates as the minimum selectable date. So a customer can not book within x days from today's date.

If you set it to “1”, then no one can book for tonight. The first bookable night is tomorrow night.

Override setting per accommodation type

You can have different opening dates for an accommodation type. In the Accommodation Type settings, you will an option to “Override default opening dates”. If you wish to prevent last minute booking only for some accommodation type, you can do so. You will create the general rule in HBook > Misc > Opening dates, and will override this setting for the accommodation types that do not follow the general rule.