diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1aaf77d..c7101a3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,5 @@
 ## Unreleased
+* Fix negative playtimes being considered positive
 * Add %d for days to common.util.time.format_duration
 * Set up tests, add tests for common.util.time
 * Display total hours played on homepage
diff --git a/src/web/common/util/time.py b/src/web/common/util/time.py
index 82b7ff4..f707f86 100644
--- a/src/web/common/util/time.py
+++ b/src/web/common/util/time.py
@@ -23,6 +23,9 @@ def format_duration(
     hour_seconds = 60 * minute_seconds
     day_seconds = 24 * hour_seconds
     seconds_total = int(duration.total_seconds())
+    # timestamps where end is before start
+    if seconds_total < 0:
+        seconds_total = 0
     days, remainder = divmod(seconds_total, day_seconds)
     hours, remainder = divmod(remainder, hour_seconds)
     minutes, seconds = divmod(remainder, minute_seconds)
diff --git a/tests/test_time.py b/tests/test_time.py
index 53a74f4..98b713c 100644
--- a/tests/test_time.py
+++ b/tests/test_time.py
@@ -51,3 +51,8 @@ class FormatDurationTest(unittest.TestCase):
         self.assertEqual(
             result, "50 days, 10 hours, 34 minutes, 24 seconds, 4358064 total seconds"
         )
+
+    def test_negative(self):
+        delta = timedelta(hours=-2)
+        result = format_duration(delta, "%H hours")
+        self.assertEqual(result, "0 hours")