diff --git a/distributed/cli/tests/test_dask_scheduler.py b/distributed/cli/tests/test_dask_scheduler.py
index a407a2b8fe1..f69ec48127b 100644
--- a/distributed/cli/tests/test_dask_scheduler.py
+++ b/distributed/cli/tests/test_dask_scheduler.py
@@ -236,11 +236,13 @@ def test_dashboard_port_zero(loop):
         with popen(["dask-scheduler", "--dashboard-address", ":0"]) as proc:
             count = 0
             while count < 1:
-                line = proc.stderr.readline()
-                if b"dashboard" in line.lower():
+                line = proc.stderr.readline().decode("utf8")
+                if "dashboard" in line.lower():
                     sleep(0.01)
                     count += 1
-                    assert b":0" not in line
+                    # Remove timestamp from logging line which may contain ":0"
+                    line = " - ".join(line.split(" - ")[1:])
+                    assert ":0" not in line
 
 
 PRELOAD_TEXT = """
diff --git a/distributed/distributed.yaml b/distributed/distributed.yaml
index c71845e3769..2c3ce96ba0a 100644
--- a/distributed/distributed.yaml
+++ b/distributed/distributed.yaml
@@ -182,7 +182,7 @@ distributed:
 
     max-error-length: 10000 # Maximum size traceback after error to return
     log-length: 10000  # default length of logs to keep in memory
-    log-format: '%(name)s - %(levelname)s - %(message)s'
+    log-format: '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
     pdb-on-err: False       # enter debug mode on scheduling error
     system-monitor:
       interval: 500ms
diff --git a/distributed/tests/test_config.py b/distributed/tests/test_config.py
index 200493a822c..4d8ca7afab9 100644
--- a/distributed/tests/test_config.py
+++ b/distributed/tests/test_config.py
@@ -91,10 +91,12 @@ def test_logging_default():
         foreign_log = foreign_log.getvalue().splitlines()
 
         # distributed log is configured at INFO level by default
-        assert distributed_log == [
+        expected_log_suffix = [
             "distributed - INFO - 2: info",
             "distributed.foo.bar - INFO - 3: info",
         ]
+        for result, expected_suffix in zip(distributed_log, expected_log_suffix):
+            assert result.endswith(expected_suffix)
 
         # foreign logs should be unaffected by distributed's logging
         # configuration.  They get the default ERROR level from logging.
@@ -139,10 +141,13 @@ def test_logging_simple_under_distributed():
 
             distributed_log = distributed_log.getvalue().splitlines()
 
-            assert distributed_log == [
+            expected_log_suffix = [
                 "distributed.foo - INFO - 1: info",
                 "distributed.foo.bar - ERROR - 3: error",
-                ], (dask.config.config, distributed_log)
+            ]
+
+            for result, expected_suffix in zip(distributed_log, expected_log_suffix):
+                assert result.endswith(expected_suffix), (dask.config.config, distributed_log)
             """
 
         subprocess.check_call([sys.executable, "-c", code])
@@ -174,10 +179,13 @@ def test_logging_simple():
 
             distributed_log = distributed_log.getvalue().splitlines()
 
-            assert distributed_log == [
+            expected_log_suffix = [
                 "distributed.foo - INFO - 1: info",
                 "distributed.foo.bar - ERROR - 3: error",
-                ], (dask.config.config, distributed_log)
+            ]
+
+            for result, expected_suffix in zip(distributed_log, expected_log_suffix):
+                assert result.endswith(expected_suffix), (dask.config.config, distributed_log)
             """
 
         subprocess.check_call([sys.executable, "-c", code])
diff --git a/setup.cfg b/setup.cfg
index 6016c5fb133..367862473cd 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -51,6 +51,7 @@ filterwarnings =
 minversion = 4
 markers =
     slow: marks tests as slow (deselect with '-m "not slow"')
+    asyncio: marks tests that test async functionality
     avoid_ci: marks tests as flaky on CI on all OSs
     ipython: marks tests as exercising IPython
 timeout_method = thread