using System;

using System.Linq.Expressions;

​

public class Model {

    public DateTime Date { get; set; }  

}

public class Program

{

    public static void Main()

    {

        ParameterExpression param = Expression.Parameter(typeof(Model), "x");

        var property = Expression.Property(param, "Date");

        ConstantExpression constant = Expression.Constant(new DateTime(2015, 1, 1), typeof(DateTime));

        Expression finalExpression = Expression.LessThanOrEqual(property, constant);

        var tree = Expression.Lambda<Func<Model, bool>>(finalExpression, param);

        Console.WriteLine(tree);

        Expression<Func<Model, bool>> handMaidExpression = x => x.Date == new DateTime(2015, 1, 1);

        Console.WriteLine(handMaidExpression);

    }

}