diff --git a/src/Snap.Hutao/Snap.Hutao.Test/IncomingFeature/SpiralAbyssScheduleIdTest.cs b/src/Snap.Hutao/Snap.Hutao.Test/IncomingFeature/SpiralAbyssScheduleIdTest.cs
new file mode 100644
index 00000000..31d30681
--- /dev/null
+++ b/src/Snap.Hutao/Snap.Hutao.Test/IncomingFeature/SpiralAbyssScheduleIdTest.cs
@@ -0,0 +1,42 @@
+using System;
+
+namespace Snap.Hutao.Test.IncomingFeature;
+
+[TestClass]
+public class SpiralAbyssScheduleIdTest
+{
+    private static readonly TimeSpan Utc8 = new(8, 0, 0);
+
+    [TestMethod]
+    public void Test()
+    {
+        Console.WriteLine($"当前第 {GetForDateTimeOffset(DateTimeOffset.Now)} 期");
+
+        DateTimeOffset dateTimeOffset = new(2020, 7, 1, 4, 0, 0, Utc8);
+        Console.WriteLine($"2020-07-01 04:00:00 为第 {GetForDateTimeOffset(dateTimeOffset)} 期");
+    }
+    public static int GetForDateTimeOffset(DateTimeOffset dateTimeOffset)
+    {
+        // Force time in UTC+08
+        dateTimeOffset = dateTimeOffset.ToOffset(Utc8);
+
+        ((int year, int mouth, int day), (int hour, _), _) = dateTimeOffset;
+
+        // 2020-07-01 04:00:00 为第 1 期
+        int periodNum = (((year - 2020) * 12) + (mouth - 6)) * 2;
+
+        // 上半月：1-15 日, 以及 16 日 00:00-04:00
+        if (day < 16 || (day == 16 && hour < 4))
+        {
+            periodNum--;
+        }
+
+        // 上个月：1 日 00:00-04:00
+        if (day is 1 && hour < 4)
+        {
+            periodNum--;
+        }
+
+        return periodNum;
+    }
+}
\ No newline at end of file
diff --git a/src/Snap.Hutao/Snap.Hutao.Test/RuntimeBehavior/UnsafeRuntimeBehaviorTest.cs b/src/Snap.Hutao/Snap.Hutao.Test/RuntimeBehavior/UnsafeRuntimeBehaviorTest.cs
index d876b35b..b2b4ed03 100644
--- a/src/Snap.Hutao/Snap.Hutao.Test/RuntimeBehavior/UnsafeRuntimeBehaviorTest.cs
+++ b/src/Snap.Hutao/Snap.Hutao.Test/RuntimeBehavior/UnsafeRuntimeBehaviorTest.cs
@@ -1,10 +1,15 @@
-namespace Snap.Hutao.Test.RuntimeBehavior;
+using System;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace Snap.Hutao.Test.RuntimeBehavior;
 
 [TestClass]
 public sealed class UnsafeRuntimeBehaviorTest
 {
     [TestMethod]
-    public unsafe void UInt32AllSetIs()
+    public unsafe void UInt32AllSetIsUInt32MaxValue()
     {
         byte[] bytes =
 #if NET8_0_OR_GREATER
@@ -18,23 +23,28 @@ public sealed class UnsafeRuntimeBehaviorTest
             Assert.AreEqual(uint.MaxValue, *(uint*)pBytes);
         }
     }
-}
 
-[TestClass]
-public sealed class NewModifierRuntimeBehaviorTest
-{
-    private interface IBase
+    [TestMethod]
+    public unsafe void ReadOnlyStructCanBeModifiedInCtor()
     {
-        int GetValue();
+        TestStruct testStruct = new([4444, 7878, 5656, 1212]);
+
+        Assert.AreEqual(4444, testStruct.Value1);
+        Assert.AreEqual(7878, testStruct.Value2);
+        Assert.AreEqual(5656, testStruct.Value3);
+        Assert.AreEqual(1212, testStruct.Value4);
     }
 
-    private interface IBaseImpl : IBase
+    private readonly struct TestStruct
     {
-        new int GetValue();
-    }
+        public readonly int Value1;
+        public readonly int Value2;
+        public readonly int Value3;
+        public readonly int Value4;
 
-    private sealed class Impl : IBaseImpl
-    {
-        public int GetValue() => 1;
+        public TestStruct(List<int> list)
+        {
+            CollectionsMarshal.AsSpan(list).CopyTo(MemoryMarshal.CreateSpan(ref Unsafe.As<TestStruct, int>(ref this), 4));
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Snap.Hutao/Snap.Hutao.Test/Snap.Hutao.Test.csproj b/src/Snap.Hutao/Snap.Hutao.Test/Snap.Hutao.Test.csproj
index 6dc31b33..b9f4d0b3 100644
--- a/src/Snap.Hutao/Snap.Hutao.Test/Snap.Hutao.Test.csproj
+++ b/src/Snap.Hutao/Snap.Hutao.Test/Snap.Hutao.Test.csproj
@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net7.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net8.0</TargetFrameworks>
     <ImplicitUsings>disable</ImplicitUsings>
     <Nullable>enable</Nullable>
     <IsPackable>false</IsPackable>