diff --git a/src/analyzers/velocity.py b/src/analyzers/velocity.py
index 151a2c7..de28847 100644
--- a/src/analyzers/velocity.py
+++ b/src/analyzers/velocity.py
@@ -1,67 +1,77 @@
-from dataclasses import dataclass
-from typing import Dict, Optional
+from collections import defaultdict
+from typing import Dict
 
 from src.analyzers.git_repository import GitRepository
-from src.models.data_structures import VelocityAnalysis
+from src.models import VelocityAnalysis
 
 
-@dataclass
 class VelocityAnalyzer:
-    """Analyzes team velocity."""
+    """Analyze development velocity and productivity."""
 
-    repo: GitRepository
-    days: int
+    def __init__(
+        self,
+        repo: GitRepository,
+        days: int = 30,
+    ) -> None:
+        """Initialize VelocityAnalyzer."""
+        self.repo = repo
+        self.days = days
 
-    def analyze(self) -> Optional[VelocityAnalysis]:
-        """Analyze team velocity."""
-        commits = self.repo.get_commits()
+    def analyze(self) -> VelocityAnalysis:
+        """Analyze velocity metrics."""
+        commits = self.repo.get_commits(since_days=self.days)
 
         if not commits:
-            return None
+            return VelocityAnalysis()
 
-        authors = self.repo.get_authors()
-        authors.sort(key=lambda a: a.commit_count, reverse=True)
-        top_contributors = authors[:10]
+        total_commits = len(commits)
+        commits_per_day = total_commits / max(self.days, 1)
+        commits_per_week = total_commits / max(self.days / 7, 1)
 
-        commits_per_day = len(commits) / max(1, self.days)
-        commits_per_week = commits_per_day * 7
-        commits_per_month = commits_per_day * 30
+        daily_totals = defaultdict(int)
+        weekly_totals = defaultdict(int)
 
-        commits_by_day: Dict[str, int] = {}
-        commits_by_hour: Dict[str, int] = {}
+        day_counts = defaultdict(int)
+        hour_counts = defaultdict(int)
 
         for commit in commits:
-            day_key = commit.timestamp.strftime("%A")
-            hour_key = commit.timestamp.strftime("%H:00")
+            day_key = commit.author_datetime.strftime("%Y-%m-%d")
+            week_key = commit.author_datetime.strftime("%Y-W%W")
+            day_name = commit.author_datetime.strftime("%A")
+            hour = commit.author_datetime.strftime("%H:00")
 
-            commits_by_day[day_key] = commits_by_day.get(day_key, 0) + 1
-            commits_by_hour[hour_key] = commits_by_hour.get(hour_key, 0) + 1
+            daily_totals[day_key] += 1
+            weekly_totals[week_key] += 1
+            day_counts[day_name] += 1
+            hour_counts[hour] += 1
 
-        most_active_day = max(commits_by_day, key=commits_by_day.get) if commits_by_day else "N/A"
-        most_active_hour = max(commits_by_hour, key=commits_by_hour.get) if commits_by_hour else "N/A"
+        most_active_day = max(day_counts, key=day_counts.get) if day_counts else ""
+        most_active_hour = max(hour_counts, key=hour_counts.get) if hour_counts else ""
 
-        if len(commits) >= 2:
-            recent_commits = commits[:10]
-            older_commits = commits[10:20]
-
-            recent_avg = sum(1 for _ in recent_commits) / max(1, len(recent_commits))
-            older_avg = sum(1 for _ in older_commits) / max(1, len(older_commits))
-
-            if recent_avg > older_avg * 1.1:
-                velocity_trend = "increasing"
-            elif recent_avg < older_avg * 0.9:
-                velocity_trend = "decreasing"
+        if len(weekly_totals) >= 2:
+            weeks = sorted(weekly_totals.keys())
+            recent_weeks = weeks[-2:]
+            if len(recent_weeks) == 2:
+                current = weekly_totals[recent_weeks[1]]
+                previous = weekly_totals[recent_weeks[0]]
+                if current > previous:
+                    velocity_trend = "increasing"
+                elif current < previous:
+                    velocity_trend = "decreasing"
+                else:
+                    velocity_trend = "stable"
             else:
                 velocity_trend = "stable"
         else:
             velocity_trend = "stable"
 
         return VelocityAnalysis(
-            commits_per_day=commits_per_day,
-            commits_per_week=commits_per_week,
-            commits_per_month=commits_per_month,
+            total_commits=total_commits,
+            commits_per_day=round(commits_per_day, 2),
+            commits_per_week=round(commits_per_week, 2),
             velocity_trend=velocity_trend,
-            top_contributors=top_contributors,
             most_active_day=most_active_day,
             most_active_hour=most_active_hour,
+            weekly_totals=dict(weekly_totals),
+            daily_totals=dict(daily_totals),
         )