The correct answer is: 105 days
A property must actually be let for 105 days during the tax year (previously 70 days) to satisfy the letting condition to be treated as a FHL.
The property must be available for letting for at least 210 days
Note. If a landlord owns a number of furnished holiday accommodation properties and one of them fails to satisfy this condition (but satisfies the other FHL conditions) he can elect to average the number of days of all his properties to determine whether the property qualifies.