diff --git a/Zframework/theme.lua b/Zframework/theme.lua
index ac847cf3..6f32dc71 100644
--- a/Zframework/theme.lua
+++ b/Zframework/theme.lua
@@ -38,9 +38,10 @@ function THEME.calculate(Y,M,D)
         --Z day
         D=='26'and(
             (M=='01'or M=='02'or M=='03')and'zday1'or
-            (M=='04'or M=='05'or M=='06')and'zday2'or
-            (M=='07'or M=='08'or M=='09')and'zday3'or
-            (M=='10'or M=='11'or M=='12')and'zday4'
+            (M=='04'or M=='05')and'zday2'or
+            (M=='06'or M=='07')and'zday3'or
+            (M=='08'or M=='09')and'zday4'or
+            (M=='10'or M=='11'or M=='12')and'zday5'
         )or
 
         'classic'
@@ -63,16 +64,19 @@ function THEME.set(theme)
         MES.new('info',"★☆新年快乐☆★")
     elseif theme=='zday1'then
         BG.setDefault('lanterns')
-        BGM.setDefault('overzero')
+        BGM.setDefault('blank')
     elseif theme=='zday2'then
         BG.setDefault('lanterns')
-        BGM.setDefault('vacuum')
+        BGM.setDefault('overzero')
     elseif theme=='zday3'then
         BG.setDefault('lanterns')
-        BGM.setDefault('empty')
+        BGM.setDefault('vacuum')
     elseif theme=='zday4'then
         BG.setDefault('lanterns')
-        BGM.setDefault('space')
+        BGM.setDefault('jazz nihilism')
+    elseif theme=='zday5'then
+        BG.setDefault('lanterns')
+        BGM.setDefault('empty')
     elseif theme=='fool'then
         BG.setDefault('blockrain')
         BGM.setDefault('how feeling')
diff --git a/media/BGM/jazz nihilism.ogg b/media/BGM/jazz nihilism.ogg
new file mode 100644
index 00000000..a981f96d
Binary files /dev/null and b/media/BGM/jazz nihilism.ogg differ
diff --git a/parts/scenes/music.lua b/parts/scenes/music.lua
index 0daad2cc..c17d6a26 100644
--- a/parts/scenes/music.lua
+++ b/parts/scenes/music.lua
@@ -16,6 +16,7 @@ local author={
     ["how feeling"]="????",
     moonbeam="Beethoven & MrZ",
     ["secret7th remix"]="柒栎流星",
+    ["jazz nihilism"]="Trebor",
 }
 
 local scene={}
diff --git a/parts/updateLog.lua b/parts/updateLog.lua
index a6c731c2..0172170d 100644
--- a/parts/updateLog.lua
+++ b/parts/updateLog.lua
@@ -34,6 +34,7 @@ return[=[
         新增:
                 新增ARS_Z旋转系统:简化复杂的测试逻辑,统一使用{右,左}(i块为{上,上2},五连块风格模仿)
                 添加SRS_X旋转系统:基于SRS,I块和除了PQ的非四连块使用TRS的表
+                新BGM:Jazz nihilism(用于节日主题,by Trebor)
         改动:
                 增大场地晃动的阻力,看起来更舒服
                 平滑下落的消行动画曲线稍微拉直一些