diff --git a/gitstats b/gitstats
index 34151af..8f7b4a7 100755
--- a/gitstats
+++ b/gitstats
@@ -159,6 +159,8 @@ class GitDataCollector(DataCollector):
 		self.activity_by_hour_of_week = {} # weekday -> hour -> commits
 		self.activity_by_hour_of_day_busiest = 0
 		self.activity_by_hour_of_week_busiest = 0
+		self.activity_by_year_week = {} # yy_wNN -> commits
+		self.activity_by_year_week_peak = 0
 
 		self.authors = {} # name -> {commits, first_commit_stamp, last_commit_stamp, last_active_day, active_days}
 
@@ -265,6 +267,15 @@ class GitDataCollector(DataCollector):
 			else:
 				self.activity_by_month_of_year[month] = 1
 
+			# yearly/weekly activity
+			yyw = date.strftime('%Y-%W')
+			if yyw not in self.activity_by_year_week:
+				self.activity_by_year_week[yyw] = 1
+			else:
+				self.activity_by_year_week[yyw] += 1
+			if self.activity_by_year_week_peak < self.activity_by_year_week[yyw]:
+				self.activity_by_year_week_peak = self.activity_by_year_week[yyw]
+
 			# author stats
 			if author not in self.authors:
 				self.authors[author] = {}
@@ -546,6 +557,39 @@ class HTMLReportCreator(ReportCreator):
 
 		#f.write('<h2>Last 12 months</h2>')
 
+		# Weekly activity
+		WEEKS = 32
+		f.write(html_header(2, 'Weekly activity'))
+		f.write('<p>Last %d weeks</p>' % WEEKS)
+
+		# generate weeks to show (previous N weeks from now)
+		now = datetime.datetime.now()
+		deltaweek = datetime.timedelta(7)
+		weeks = []
+		stampcur = now
+		for i in range(0, WEEKS):
+			weeks.insert(0, stampcur.strftime('%Y-%W'))
+			stampcur -= deltaweek
+
+		# top row: commits & bar
+		f.write('<table class="noborders"><tr>')
+		for i in range(0, WEEKS):
+			commits = 0
+			if weeks[i] in data.activity_by_year_week:
+				commits = data.activity_by_year_week[weeks[i]]
+
+			percentage = 0
+			if weeks[i] in data.activity_by_year_week:
+				percentage = float(data.activity_by_year_week[weeks[i]]) / data.activity_by_year_week_peak
+			height = max(1, int(200 * percentage))
+			f.write('<td style="text-align: center; vertical-align: bottom">%d<div style="display: block; background-color: red; width: 20px; height: %dpx"></div></td>' % (commits, height))
+
+		# bottom row: year/week
+		f.write('</tr><tr>')
+		for i in range(0, WEEKS):
+			f.write('<td>%s</td>' % (WEEKS - i))
+		f.write('</tr></table>')
+
 		# Hour of Day
 		f.write(html_header(2, 'Hour of Day'))
 		hour_of_day = data.getActivityByHourOfDay()
diff --git a/gitstats.css b/gitstats.css
index 7dcbf88..8710cf3 100644
--- a/gitstats.css
+++ b/gitstats.css
@@ -28,6 +28,14 @@ table {
 	margin-bottom: 1em;
 }
 
+table.noborders {
+	border: none;
+}
+
+table.noborders td {
+	border: none;
+}
+
 .vtable {
 	float: right;
 	clear: both;