diff --git a/.claude/JOURNAL.md b/.claude/JOURNAL.md
index 1dd9976..0fd3a22 100644
--- a/.claude/JOURNAL.md
+++ b/.claude/JOURNAL.md
@@ -240,3 +240,6 @@ This journal tracks substantive work on documents, diagrams, and documentation c
 
 79. **Task - Activity tracking methodology research**: Documented industry approaches for activity scoring<br>
     **Result**: Created `docs/activity-tracking-methodology.md` covering: (1) Exponential Moving Average with decay - our current approach using half-life parameterization, (2) Time-Window Percentage (Hubstaff) - active seconds per 10-min window with 60-80% typical for development, (3) Daily Target (8h=100%) - maps to work expectations, (4) GitHub Contribution Graph - threshold-based intensity levels. Research confirms our EMA approach is industry-standard. Key insight from Hubstaff: 100% activity is unrealistic, typical ranges 30-80% depending on role
+
+80. **Task - Activity monitor half-life to 48h**: Changed decay half-life default from 24h to 48h<br>
+    **Result**: Updated JUPYTERHUB_ACTIVITYMON_HALF_LIFE default across Dockerfile, custom_handlers.py (DEFAULT_HALF_LIFE constant), activity_sampler.py (code and docstring), settings_dictionary.yml, and README.md. With 48h half-life, a sample from 48 hours ago has 50% weight, providing smoother decay for activity scoring
diff --git a/README.md b/README.md
index 0d87bf3..c0c483b 100644
--- a/README.md
+++ b/README.md
@@ -392,7 +392,7 @@ services:
     environment:
       - JUPYTERHUB_ACTIVITYMON_SAMPLE_INTERVAL=600   # 10 minutes (default) - how often to record samples
       - JUPYTERHUB_ACTIVITYMON_RETENTION_DAYS=7      # 7 days (default) - how long to keep samples
-      - JUPYTERHUB_ACTIVITYMON_HALF_LIFE=24          # 24 hours (default) - decay half-life for scoring
+      - JUPYTERHUB_ACTIVITYMON_HALF_LIFE=48          # 48 hours (default) - decay half-life for scoring
       - JUPYTERHUB_ACTIVITYMON_INACTIVE_AFTER=60     # 60 minutes (default) - threshold for inactive status
 ```
 
diff --git a/services/jupyterhub/Dockerfile.jupyterhub b/services/jupyterhub/Dockerfile.jupyterhub
index e415a64..54feaf9 100644
--- a/services/jupyterhub/Dockerfile.jupyterhub
+++ b/services/jupyterhub/Dockerfile.jupyterhub
@@ -90,7 +90,7 @@ ENV JUPYTERHUB_IDLE_CULLER_MAX_EXTENSION=24
 # Activity monitor
 ENV JUPYTERHUB_ACTIVITYMON_SAMPLE_INTERVAL=600
 ENV JUPYTERHUB_ACTIVITYMON_RETENTION_DAYS=7
-ENV JUPYTERHUB_ACTIVITYMON_HALF_LIFE=24
+ENV JUPYTERHUB_ACTIVITYMON_HALF_LIFE=48
 ENV JUPYTERHUB_ACTIVITYMON_INACTIVE_AFTER=60
 ENV JUPYTERHUB_ACTIVITYMON_RESOURCES_UPDATE_INTERVAL=10
 ENV JUPYTERHUB_ACTIVITYMON_VOLUMES_UPDATE_INTERVAL=3600
diff --git a/services/jupyterhub/conf/bin/activity_sampler.py b/services/jupyterhub/conf/bin/activity_sampler.py
index 706b31b..6ff0e8d 100644
--- a/services/jupyterhub/conf/bin/activity_sampler.py
+++ b/services/jupyterhub/conf/bin/activity_sampler.py
@@ -14,7 +14,7 @@ Environment Variables:
     JUPYTERHUB_API_URL: Hub API URL (provided by JupyterHub)
     JUPYTERHUB_ACTIVITYMON_SAMPLE_INTERVAL: Sampling interval in seconds (default: 600)
     JUPYTERHUB_ACTIVITYMON_RETENTION_DAYS: Days to retain samples (default: 7)
-    JUPYTERHUB_ACTIVITYMON_HALF_LIFE: Score decay half-life in hours (default: 24)
+    JUPYTERHUB_ACTIVITYMON_HALF_LIFE: Score decay half-life in hours (default: 48)
     JUPYTERHUB_ACTIVITYMON_INACTIVE_AFTER: Minutes before marking inactive (default: 60)
 """
 
@@ -71,7 +71,7 @@ class ActivitySamplerService:
         # Sampling configuration
         self.sample_interval = int(os.environ.get('JUPYTERHUB_ACTIVITYMON_SAMPLE_INTERVAL', 600))
         self.retention_days = int(os.environ.get('JUPYTERHUB_ACTIVITYMON_RETENTION_DAYS', 7))
-        self.half_life_hours = int(os.environ.get('JUPYTERHUB_ACTIVITYMON_HALF_LIFE', 24))
+        self.half_life_hours = int(os.environ.get('JUPYTERHUB_ACTIVITYMON_HALF_LIFE', 48))
         self.inactive_after_minutes = int(os.environ.get('JUPYTERHUB_ACTIVITYMON_INACTIVE_AFTER', 60))
 
         # Database
diff --git a/services/jupyterhub/conf/bin/custom_handlers.py b/services/jupyterhub/conf/bin/custom_handlers.py
index b66ee79..1cda88c 100755
--- a/services/jupyterhub/conf/bin/custom_handlers.py
+++ b/services/jupyterhub/conf/bin/custom_handlers.py
@@ -94,7 +94,7 @@ class ActivityMonitor:
 
     # Default configuration
     DEFAULT_RETENTION_DAYS = 7       # 7 days
-    DEFAULT_HALF_LIFE = 24           # 24 hours
+    DEFAULT_HALF_LIFE = 48           # 48 hours
     DEFAULT_INACTIVE_AFTER = 60      # 60 minutes
     DEFAULT_ACTIVITY_UPDATE_INTERVAL = 600  # 10 minutes
 
diff --git a/services/jupyterhub/conf/settings_dictionary.yml b/services/jupyterhub/conf/settings_dictionary.yml
index b590e14..83a9c57 100644
--- a/services/jupyterhub/conf/settings_dictionary.yml
+++ b/services/jupyterhub/conf/settings_dictionary.yml
@@ -87,7 +87,7 @@ Activity Monitor:
 
   - name: JUPYTERHUB_ACTIVITYMON_HALF_LIFE
     description: Decay half-life in hours (1-168)
-    default: "24"
+    default: "48"
 
   - name: JUPYTERHUB_ACTIVITYMON_INACTIVE_AFTER
     description: Minutes until user considered inactive (1-1440)