diff --git a/api/src/Sozsoft.Platform.Application/Identity/PlatformSignInResultExtensions.cs b/api/src/Sozsoft.Platform.Application/Identity/PlatformSignInResultExtensions.cs
index a620aa4..3362bb2 100644
--- a/api/src/Sozsoft.Platform.Application/Identity/PlatformSignInResultExtensions.cs
+++ b/api/src/Sozsoft.Platform.Application/Identity/PlatformSignInResultExtensions.cs
@@ -53,7 +53,11 @@ public static class PlatformSignInResultExtensions
             if (resultP.IsNotAllowed_TenantIsPassive)
             {
                 return PlatformConsts.UserCannotSignInErrors.LoginNotAllowed_TenantIsPassive;
-            }            
+            }
+            if (resultP.IsNotAllowed_WorkHour)
+            {
+                return PlatformConsts.UserCannotSignInErrors.LoginNotAllowed_WorkHour;
+            }
         }
         /// Added -->
 
diff --git a/api/src/Sozsoft.Platform.DbMigrator/Seeds/LanguagesData.json b/api/src/Sozsoft.Platform.DbMigrator/Seeds/LanguagesData.json
index 00963e7..29a17e8 100644
--- a/api/src/Sozsoft.Platform.DbMigrator/Seeds/LanguagesData.json
+++ b/api/src/Sozsoft.Platform.DbMigrator/Seeds/LanguagesData.json
@@ -3102,6 +3102,12 @@
             "en": "It's time to change your password periodically.",
             "tr": "Parolanızın periyodik olarak değiştirme zamanı gelmiştir."
         },
+        {
+            "resourceName": "Platform",
+            "key": "Abp.Identity.LoginNotAllowed_WorkHour",
+            "en": "You cannot sign in outside of the allowed work hours.",
+            "tr": "İzin verilen iş saatleri dışında giriş yapamazsınız."
+        },        
         {
             "resourceName": "Platform",
             "key": "Abp.Identity.IpRestrictionError",
diff --git a/api/src/Sozsoft.Platform.Domain.Shared/PlatformConsts.cs b/api/src/Sozsoft.Platform.Domain.Shared/PlatformConsts.cs
index edac43f..c5b7449 100644
--- a/api/src/Sozsoft.Platform.Domain.Shared/PlatformConsts.cs
+++ b/api/src/Sozsoft.Platform.Domain.Shared/PlatformConsts.cs
@@ -105,6 +105,7 @@ public static class PlatformConsts
             public const string IpRestrictionError = GroupName + ".IpRestrictionError";
             public const string LoginEndDateError = GroupName + ".LoginEndDateError";
             public const string TenantIsPassive = GroupName + ".TenantIsPassive";
+            public const string LoginNotAllowed_WorkHour = GroupName + ".LoginNotAllowed_WorkHour";
             public const string CaptchaWrongCode = GroupName + ".CaptchaWrongCode";
             public const string TwoFactorWrongCode = GroupName + ".TwoFactorWrongCode";
             public const string SignOut = GroupName + ".SignOut";
@@ -423,6 +424,7 @@ public static class PlatformConsts
         public static string ShouldChangePasswordPeriodic { get; set; } = "UserCannotSignInShouldChangePasswordPeriodic";
         public static string LoginNotAllowed_TenantIsPassive { get; set; } = "UserCannotSignInTenantIsPassive";
         public static string LoginNotAllowed_TenantNotFound { get; set; } = "UserCannotSignInTenantNotFound";
+        public static string LoginNotAllowed_WorkHour { get; set; } = "UserCannotSignInWorkHour";
     }
 
     public static class GridOptions
diff --git a/api/src/Sozsoft.Platform.Domain/Identity/PlatformSignInResult.cs b/api/src/Sozsoft.Platform.Domain/Identity/PlatformSignInResult.cs
index cbb0950..df13679 100644
--- a/api/src/Sozsoft.Platform.Domain/Identity/PlatformSignInResult.cs
+++ b/api/src/Sozsoft.Platform.Domain/Identity/PlatformSignInResult.cs
@@ -22,12 +22,14 @@ public class PlatformSignInResult : SignInResult
     /// <value>True if login end date is due, otherwise false.</value>
     public bool IsNotAllowed_LoginEndDateDue { get; set; }
 
-    public bool IsNotAllowed_TenantIsPassive { get; set; }
-
     public bool ShouldChangePasswordOnNextLogin { get; set; }
 
     public bool ShouldChangePasswordPeriodic { get; set; }
 
+    public bool IsNotAllowed_TenantIsPassive { get; set; }
+
+    public bool IsNotAllowed_WorkHour { get; set; }
+
     public override string ToString()
     {
         return
@@ -37,6 +39,7 @@ public class PlatformSignInResult : SignInResult
             ShouldChangePasswordOnNextLogin ? "ShouldChangePasswordOnNextLogin" :
             ShouldChangePasswordPeriodic ? "ShouldChangePasswordPeriodic" :
             IsNotAllowed_TenantIsPassive ? "NotAllowed_TenantIsPassive" :
+            IsNotAllowed_WorkHour ? "NotAllowed_WorkHour" :
             base.ToString();
     }
 }
diff --git a/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformEventIds.cs b/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformEventIds.cs
index fdd36c2..ef20d89 100644
--- a/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformEventIds.cs
+++ b/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformEventIds.cs
@@ -21,6 +21,9 @@ public static class PlatformEventIds
 
     public static EventId UserCannotSignInTenantIsPassive =
         new(17, PlatformConsts.UserCannotSignInErrors.LoginNotAllowed_TenantIsPassive);
+
+    public static EventId UserCannotSignInWorkHour =
+        new(18, PlatformConsts.UserCannotSignInErrors.LoginNotAllowed_WorkHour);
 }
 
 
diff --git a/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformLoginResult.cs b/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformLoginResult.cs
index 5b6d123..aaa1920 100644
--- a/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformLoginResult.cs
+++ b/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformLoginResult.cs
@@ -58,7 +58,12 @@ public class PlatformLoginResult : AbpLoginResult
             {
                 PResult = PlatformLoginResultType.TenantIsPassive;
                 Description = L[PlatformConsts.AbpIdentity.User.TenantIsPassive];
-            }            
+            }
+            else if (resultP.IsNotAllowed_WorkHour)
+            {
+                PResult = PlatformLoginResultType.NotAllowedWorkHour;
+                Description = L[PlatformConsts.AbpIdentity.User.LoginNotAllowed_WorkHour];
+            }
         }
         else
         {
diff --git a/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformLoginResultType.cs b/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformLoginResultType.cs
index 219236a..61e5138 100644
--- a/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformLoginResultType.cs
+++ b/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformLoginResultType.cs
@@ -15,5 +15,6 @@ public enum PlatformLoginResultType : byte
     LoginEndDateDue,
     ShowCaptcha,
     TenantIsPassive,
+    NotAllowedWorkHour
 }
 
diff --git a/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformSignInManager.cs b/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformSignInManager.cs
index 129285e..8b5c152 100644
--- a/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformSignInManager.cs
+++ b/api/src/Sozsoft.Platform.HttpApi.Host/Identity/PlatformSignInManager.cs
@@ -30,6 +30,7 @@ public class PlatformSignInManager : AbpSignInManager, IPlatformSignInManager
 {
     private readonly IClock clock;
     private readonly IRepository<IpRestriction, Guid> repositoryIp;
+    private readonly IRepository<WorkHour, Guid> repositoryWorkHour;
     private readonly ITenantRepository tenantRepository;
     private readonly IdentityUserManager userManager;
 
@@ -45,6 +46,7 @@ public class PlatformSignInManager : AbpSignInManager, IPlatformSignInManager
         ISettingProvider settingProvider,
         IClock clock,
         IRepository<IpRestriction, Guid> repositoryIp,
+        IRepository<WorkHour, Guid> repositoryWorkHour,
         ITenantRepository tenantRepository
         ) : base(
             userManager,
@@ -59,6 +61,7 @@ public class PlatformSignInManager : AbpSignInManager, IPlatformSignInManager
     {
         this.clock = clock;
         this.repositoryIp = repositoryIp;
+        this.repositoryWorkHour = repositoryWorkHour;
         this.tenantRepository = tenantRepository;
         this.userManager = userManager;
     }
@@ -87,10 +90,14 @@ public class PlatformSignInManager : AbpSignInManager, IPlatformSignInManager
             {
                 return new PlatformSignInResult() { IsNotAllowed_NotAllowedIp = true };
             }
-            if (!await IsTenantActiveAsync(user))
+            if (!await CanSignInTenantActiveAsync(user))
             {
                 return new PlatformSignInResult() { IsNotAllowed_TenantIsPassive = true };
             }
+            if (!await CanSignInWorkHourAsync())
+            {
+                return new PlatformSignInResult() { IsNotAllowed_WorkHour = true };
+            }
         }
         else
         {
@@ -109,10 +116,54 @@ public class PlatformSignInManager : AbpSignInManager, IPlatformSignInManager
         return result;
     }
 
+    /// <summary>
+    /// Used to prevent login outside of defined work hours.
+    /// </summary>
+    private async Task<bool> CanSignInWorkHourAsync()
+    {
+        var workHours = await repositoryWorkHour.GetListAsync();
+
+        if (workHours.IsNullOrEmpty())
+        {
+            return true;
+        }
+
+        var now = clock.Now;
+        var currentTime = now.TimeOfDay;
+        var dayOfWeek = now.DayOfWeek;
+
+        var isAllowed = workHours.Any(wh =>
+        {
+            var dayMatches = dayOfWeek switch
+            {
+                DayOfWeek.Monday => wh.Monday == true,
+                DayOfWeek.Tuesday => wh.Tuesday == true,
+                DayOfWeek.Wednesday => wh.Wednesday == true,
+                DayOfWeek.Thursday => wh.Thursday == true,
+                DayOfWeek.Friday => wh.Friday == true,
+                DayOfWeek.Saturday => wh.Saturday == true,
+                DayOfWeek.Sunday => wh.Sunday == true,
+                _ => false
+            };
+
+            if (!dayMatches) return false;
+
+            return currentTime >= wh.StartTime.TimeOfDay && currentTime <= wh.EndTime.TimeOfDay;
+        });
+
+        if (!isAllowed)
+        {
+            Logger.LogWarning(PlatformEventIds.UserCannotSignInWorkHour, "User cannot sign in outside work hours.");
+            return false;
+        }
+
+        return true;
+    }
+
     /// <summary>
     /// Tenant IsActive
     /// </summary>
-    private async Task<bool> IsTenantActiveAsync(IdentityUser user)
+    private async Task<bool> CanSignInTenantActiveAsync(IdentityUser user)
     {
         if (!user.TenantId.HasValue)
         {