using System;

using AutoMapper;

public class Program

{

    public static void Main()

    {

        Mapper.CreateMap<User, PersonalViewModel>()

            .ForMember(vm => vm.Birthday, m => m.MapFrom(

                u => (u.Birthday.HasValue) ? u.Birthday.Value.ToString("dd.MM.yyyy") : DateTime.Now.ToString("dd.MM.yyyy")));

        Mapper.CreateMap<User, SettingsViewModel>()

            .ForMember(vm => vm.UserId, m => m.MapFrom(u => u.Id))

            .ForMember(vm => vm.Personal, opt => opt.MapFrom(u => u));

        var user = new User() { Id = "2", FirstName = "Alan", LastName = "Turing", Birthday = new DateTime(1954, 6, 7) };

        var viewModel = Mapper.Map<User, SettingsViewModel>(user);  

        viewModel.Dump();

    }

    public class SettingsViewModel

    {

        public string UserId { get; set; }

        public PersonalViewModel Personal { get; set; }

    }

    public class PersonalViewModel

    {

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public string Birthday { get; set; }

    }

    public class User

    {

        public string Id { get; set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public DateTime? Birthday { get; set; }

    }   

}