diff --git a/src/rosbags/rosbag1/reader.py b/src/rosbags/rosbag1/reader.py
index cdab0ef6..fb9fb0c4 100644
--- a/src/rosbags/rosbag1/reader.py
+++ b/src/rosbags/rosbag1/reader.py
@@ -94,7 +94,7 @@ class Chunk(NamedTuple):
 class TopicInfo(NamedTuple):
     """Topic information."""
 
-    conn_count: int
+    conncount: int
     msgcount: int
     msgdef: str
     msgtype: str
@@ -472,7 +472,7 @@ class Reader:
 
     @property
     def end_time(self) -> int:
-        """Timestamp in nanoseconds of the latest message."""
+        """Timestamp in nanoseconds after the latest message."""
         return max(x.end_time for x in self.chunk_infos)
 
     @property
@@ -517,7 +517,7 @@ class Reader:
 
         chunk_pos = header.get_uint64('chunk_pos')
         start_time = header.get_time('start_time')
-        end_time = header.get_time('end_time')
+        end_time = header.get_time('end_time') + 1
         count = header.get_uint32('count')
 
         self.bio.seek(4, os.SEEK_CUR)
diff --git a/src/rosbags/rosbag2/reader.py b/src/rosbags/rosbag2/reader.py
index 3fac5ff2..a38e0f47 100644
--- a/src/rosbags/rosbag2/reader.py
+++ b/src/rosbags/rosbag2/reader.py
@@ -121,7 +121,7 @@ class Reader:
     @property
     def duration(self) -> int:
         """Duration in nanoseconds between earliest and latest messages."""
-        return self.metadata['duration']['nanoseconds']
+        return self.metadata['duration']['nanoseconds'] + 1
 
     @property
     def start_time(self) -> int:
@@ -130,7 +130,7 @@ class Reader:
 
     @property
     def end_time(self) -> int:
-        """Timestamp in nanoseconds of the latest message."""
+        """Timestamp in nanoseconds after the latest message."""
         return self.start_time + self.duration
 
     @property
diff --git a/src/rosbags/rosbag2/writer.py b/src/rosbags/rosbag2/writer.py
index 042b096e..23d4c701 100644
--- a/src/rosbags/rosbag2/writer.py
+++ b/src/rosbags/rosbag2/writer.py
@@ -185,7 +185,7 @@ class Writer:  # pylint: disable=too-many-instance-attributes
         self.cursor = None
 
         duration, start, count = self.conn.execute(
-            'SELECT max(timestamp) - min(timestamp) + 1, min(timestamp), count(*) FROM messages',
+            'SELECT max(timestamp) - min(timestamp), min(timestamp), count(*) FROM messages',
         ).fetchone()
 
         self.conn.commit()
diff --git a/tests/test_reader.py b/tests/test_reader.py
index d603e587..66d1d02d 100644
--- a/tests/test_reader.py
+++ b/tests/test_reader.py
@@ -120,9 +120,9 @@ def bag(request: SubRequest, tmp_path: Path) -> Path:
 def test_reader(bag: Path):
     """Test reader and deserializer on simple bag."""
     with Reader(bag) as reader:
-        assert reader.duration == 42
+        assert reader.duration == 43
         assert reader.start_time == 666
-        assert reader.end_time == 708
+        assert reader.end_time == 709
         assert reader.message_count == 4
         if reader.compression_mode:
             assert reader.compression_format == 'zstd'
diff --git a/tests/test_reader1.py b/tests/test_reader1.py
index 9004f6f3..294e052b 100644
--- a/tests/test_reader1.py
+++ b/tests/test_reader1.py
@@ -198,9 +198,9 @@ def test_reader(tmp_path):  # pylint: disable=too-many-statements
     )
     with Reader(bag) as reader:
         assert reader.message_count == 1
-        assert reader.duration == 0
+        assert reader.duration == 1
         assert reader.start_time == 42 * 10**9
-        assert reader.end_time == 42 * 10**9
+        assert reader.end_time == 42 * 10**9 + 1
         assert len(reader.topics.keys()) == 1
         assert reader.topics['/topic0'].msgcount == 1
         msgs = list(reader.messages())
@@ -220,9 +220,9 @@ def test_reader(tmp_path):  # pylint: disable=too-many-statements
     )
     with Reader(bag) as reader:
         assert reader.message_count == 2
-        assert reader.duration == 5 * 10**9
+        assert reader.duration == 5 * 10**9 + 1
         assert reader.start_time == 5 * 10**9
-        assert reader.end_time == 10 * 10**9
+        assert reader.end_time == 10 * 10**9 + 1
         assert len(reader.topics.keys()) == 1
         assert reader.topics['/topic0'].msgcount == 2
         msgs = list(reader.messages())