DateFormatter's returns nil for specific date strings without time in Swift
Solution 1:
You just need to set your date formatter calendar property:
Xcode 8.2.1 • Swift 3.0.2
let dateFormatter = DateFormatter()
dateFormatter.calendar = Calendar(identifier: .iso8601)
dateFormatter.locale = Locale(identifier: "es")
dateFormatter.dateFormat = "dd 'de' MMMM"
dateFormatter.date(from: "8 de octubre") // "Oct 8, 2000, 1:00 AM"