Using apple's formatter to get Chinese yang calendar detail

gistfile1.txt

        let calendar = Calendar(identifier: .chinese)
        
        let formatter = DateFormatter()
        formatter.calendar = calendar
        formatter.dateStyle = .long
        let regex = try? NSRegularExpression(pattern: ##"(\w*)-(\w*)"##)
        let str = formatter.string(from: self)
        let matches = regex?.matches(in: str, options: [], range: NSRange(location: 0, length: str.count))
    
        var dizhi: String?
        
        matches?.forEach { (result) in
            let ns = (str as NSString)
            dizhi = ns.substring(with: result.range(at: 2))
        }