diff --git a/.gitignore b/.gitignore
index c6cc67a..7d240a3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,4 +31,5 @@ _UpgradeReport_Files/
 
 Thumbs.db
 Desktop.ini
-.DS_Store
\ No newline at end of file
+.DS_Store
+.fake
\ No newline at end of file
diff --git a/Okane.Application/CreateExpenseRequest.cs b/Okane.Application/CreateExpenseRequest.cs
index 1e59ee8..09c1e96 100644
--- a/Okane.Application/CreateExpenseRequest.cs
+++ b/Okane.Application/CreateExpenseRequest.cs
@@ -1,17 +1,22 @@
+using System;
 using System.ComponentModel.DataAnnotations;
 
-namespace Okane.Application;
-
-public class CreateExpenseRequest
+namespace Okane.Application
 {
-    [Required]
-    [Range(1, 1_000_000, ErrorMessage = "Amount is out of range")]
-    public int Amount { get; set; }
-    
-    [Required]
-    [MaxLength(80, ErrorMessage = "Category is too long")]
-    public required string Category { get; set; }
-    
-    [MaxLength(250, ErrorMessage = "Description is too long")]
-    public string? Description { get; set; }
-}
\ No newline at end of file
+    public class CreateExpenseRequest
+    {
+        [Required]
+        [Range(1, 1_000_000, ErrorMessage = "Amount is out of range")]
+        public int Amount { get; set; }
+
+        [Required]
+        [MaxLength(80, ErrorMessage = "Category is too long")]
+        public string Category { get; set; }
+
+        [MaxLength(250, ErrorMessage = "Description is too long")]
+        public string? Description { get; set; }
+
+        [Required]
+        public DateTime DateCreated { get; set; } // Nueva propiedad para la fecha
+    }
+}
diff --git a/Okane.Application/DataAnnotationsValidator.cs b/Okane.Application/DataAnnotationsValidator.cs
index 389623c..8351889 100644
--- a/Okane.Application/DataAnnotationsValidator.cs
+++ b/Okane.Application/DataAnnotationsValidator.cs
@@ -1,25 +1,33 @@
+using System;
+using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations;
+using System.Linq;
 
-namespace Okane.Application;
-
-public class DataAnnotationsValidator<T>
+namespace Okane.Application
 {
-    public IDictionary<string, string[]> Validate(T obj)
+    public class DataAnnotationsValidator<T>
     {
-        var results = new List<ValidationResult>();
+        public IDictionary<string, string[]> Validate(T obj)
+        {
+            if (obj == null)
+            {
+                throw new ArgumentNullException(nameof(obj));
+            }
+
+            var results = new List<ValidationResult>();
+            var context = new ValidationContext(
+                obj, serviceProvider: null, items: null);
 
-        var context = new ValidationContext(
-            obj, serviceProvider: null, items: null);
+            Validator.TryValidateObject(obj, context, results, validateAllProperties: true);
 
-        Validator.TryValidateObject(obj, context, results, validateAllProperties: true);
+            return results
+                .GroupBy(result => string.Join('+', result.MemberNames))
+                .ToDictionary(
+                    grouping => grouping.Key, 
+                    ToArray);
+        }
 
-        return results
-            .GroupBy(result => string.Join('+', result.MemberNames))
-            .ToDictionary(
-                grouping => grouping.Key, 
-                ToArray);
+        private static string[] ToArray(IGrouping<string, ValidationResult> grouping) => 
+            grouping.Select(result => result.ErrorMessage ?? string.Empty).ToArray();
     }
-    
-    private static string[] ToArray(IGrouping<string, ValidationResult> grouping) => 
-        grouping.Select(result => result.ErrorMessage ?? string.Empty).ToArray();
 }
\ No newline at end of file
diff --git a/Okane.Application/ExpenseResponse.cs b/Okane.Application/ExpenseResponse.cs
index e3afef4..a46d866 100644
--- a/Okane.Application/ExpenseResponse.cs
+++ b/Okane.Application/ExpenseResponse.cs
@@ -6,4 +6,5 @@ public class ExpenseResponse
     public int Amount { get; set; }
     public required string Category { get; set; }
     public string? Description { get; set; }
+    public DateTime DateCreated { get; set; } 
 }
\ No newline at end of file
diff --git a/Okane.Application/ExpenseService.cs b/Okane.Application/ExpenseService.cs
index 4c02a53..3e8de1e 100644
--- a/Okane.Application/ExpenseService.cs
+++ b/Okane.Application/ExpenseService.cs
@@ -1,57 +1,82 @@
 using Okane.Domain;
+using System;
+using System.Collections.Generic;
+using System.Linq;
 
-namespace Okane.Application;
 
-public class ExpenseService : IExpenseService
+namespace Okane.Application
 {
-    private readonly IExpensesRepository _expensesRepository;
+    public class ExpenseService : IExpenseService
+    {
+        private readonly IExpensesRepository _expensesRepository;
 
-    public ExpenseService(IExpensesRepository expensesRepository) => 
-        _expensesRepository = expensesRepository;
+        public ExpenseService(IExpensesRepository expensesRepository) => 
+            _expensesRepository = expensesRepository;
 
-    public ExpenseResponse RegisterExpense(CreateExpenseRequest request)
-    {
-        var expense = new Expense
+        public ExpenseResponse RegisterExpense(CreateExpenseRequest request)
         {
-            Amount = request.Amount,
-            Description = request.Description,
-            Category = request.Category
-        };
+            var expense = new Expense
+            {
+                Amount = request.Amount,
+                Description = request.Description,
+                Category = request.Category,
+                DateCreated = DateTime.UtcNow // Incluir la fecha actual al registrar
+            };
         
-        _expensesRepository.Add(expense);
+            _expensesRepository.Add(expense);
         
-        return CreateExpenseResponse(expense);
-    }
+            return CreateExpenseResponse(expense);
+        }
 
-    public ExpenseResponse? ById(int id)
-    {
-        var expense = _expensesRepository.ById(id);
+        public ExpenseResponse? ById(int id)
+        {
+            var expense = _expensesRepository.ById(id);
 
-        return expense == null ? null : CreateExpenseResponse(expense);
-    }
+            return expense == null ? null : CreateExpenseResponse(expense);
+        }
 
-    public IEnumerable<ExpenseResponse> Search(string? category = null) => 
-        _expensesRepository
-            .Search(category)
-            .Select(CreateExpenseResponse);
+        public IEnumerable<ExpenseResponse> Search(string? category = null) => 
+            _expensesRepository
+                .Search(category)
+                .Select(CreateExpenseResponse);
 
-    public bool Delete(int id)
-    {
-        var expenseToDelete = _expensesRepository.ById(id);
+        public bool Delete(int id)
+        {
+            var expenseToDelete = _expensesRepository.ById(id);
 
-        if (expenseToDelete == null)
-            return false;
+            if (expenseToDelete == null)
+                return false;
         
-        _expensesRepository.Delete(id);
-        return true;
-    }
+            _expensesRepository.Delete(id);
+            return true;
+        }
 
-    private static ExpenseResponse CreateExpenseResponse(Expense expense) =>
-        new()
+        public ExpenseResponse? UpdateExpense(int id, UpdateExpenseRequest request)
         {
-            Id = expense.Id,
-            Category = expense.Category,
-            Description = expense.Description,
-            Amount = expense.Amount
-        };
-}
\ No newline at end of file
+            var existingExpense = _expensesRepository.ById(id);
+            if (existingExpense == null)
+                return null;  // No se encontró el gasto para actualizar
+
+            // Actualizar la información del gasto
+            existingExpense.Amount = request.Amount;
+            existingExpense.Category = request.Category;
+            existingExpense.Description = request.Description;
+
+            // Guardar los cambios
+            _expensesRepository.Update(existingExpense);
+
+            // Devolver la respuesta actualizada
+            return CreateExpenseResponse(existingExpense);
+        }
+
+        private static ExpenseResponse CreateExpenseResponse(Expense expense) =>
+            new()
+            {
+                Id = expense.Id,
+                Category = expense.Category,
+                Description = expense.Description,
+                Amount = expense.Amount,
+                DateCreated = expense.DateCreated // Asegúrate de incluir la fecha al crear la respuesta
+            };
+    }
+}
diff --git a/Okane.Application/IExpenseService.cs b/Okane.Application/IExpenseService.cs
index 114f28c..42af95b 100644
--- a/Okane.Application/IExpenseService.cs
+++ b/Okane.Application/IExpenseService.cs
@@ -1,9 +1,29 @@
-namespace Okane.Application;
-
-public interface IExpenseService
+using Okane.Application;
+namespace Okane.Application
 {
-    ExpenseResponse RegisterExpense(CreateExpenseRequest request);
-    ExpenseResponse? ById(int id);
-    IEnumerable<ExpenseResponse> Search(string? category = null);
-    bool Delete(int id);
-}
\ No newline at end of file
+    public interface IExpenseService
+    {
+        ExpenseResponse RegisterExpense(CreateExpenseRequest request);
+        ExpenseResponse? ById(int id);
+        IEnumerable<ExpenseResponse> Search(string? category = null);
+        bool Delete(int id);
+        ExpenseResponse? UpdateExpense(int id, UpdateExpenseRequest request); 
+        
+    }
+
+    public class UpdateExpenseRequest
+
+    {
+        [Required]
+        [Range(1, 1_000_000, ErrorMessage = "Amount is out of range")]
+        public int Amount { get; set; }
+
+        [Required]
+        [MaxLength(80, ErrorMessage = "Category is too long")]
+        public string Category { get; set; }
+
+        [MaxLength(250, ErrorMessage = "Description is too long")]
+        public string? Description { get; set; }
+    }
+}
+
diff --git a/Okane.Application/IExpensesRepository.cs b/Okane.Application/IExpensesRepository.cs
index 95a565c..96cab21 100644
--- a/Okane.Application/IExpensesRepository.cs
+++ b/Okane.Application/IExpensesRepository.cs
@@ -8,4 +8,5 @@ public interface IExpensesRepository
     IEnumerable<Expense> Search(string? categoryName = null);
     void Delete(int id);
     Expense? ById(int id);
+    void Update(Expense existingExpense);
 }
\ No newline at end of file
diff --git a/Okane.Domain/Expense.cs b/Okane.Domain/Expense.cs
index 0832e55..5de2b6e 100644
--- a/Okane.Domain/Expense.cs
+++ b/Okane.Domain/Expense.cs
@@ -6,4 +6,5 @@ public class Expense
     public int Amount { get; set; }
     public required string Category { get; set; }
     public string? Description { get; set; }
+     public DateTime DateCreated { get; set; } 
 }
\ No newline at end of file