diff --git a/scripts/merge_logs.py b/scripts/merge_logs.py
index 1faf349..5ae3958 100644
--- a/scripts/merge_logs.py
+++ b/scripts/merge_logs.py
@@ -153,20 +153,31 @@
     Pattern(AUTOSERV_DATE_RE, ParseAutoservDate, lambda m: m.group(1))
 ]
 
+# 2021-07-31T07:28:33.409065Z VERBOSE1 chrome[1694:1694]: [main.cc(480)]
+CHROME_DATE_NEW_RE = re.compile(
+    r'^(\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\d.\d\d\d\d\d\dZ) ')
+
 # [8525:8525:0731/072833.409065:VERBOSE1:gaia_screen_handler.cc(480)] OnPortalDetectionCompleted Online
-CHROME_DATE_RE = re.compile(r'^\[\d+:\d+:(\d{4}/\d{6}.\d{6}):')
+CHROME_DATE_OLD_RE = re.compile(r'^\[\d+:\d+:(\d{4}/\d{6}.\d{6}):')
 ChromePatterns = [
-    Pattern(CHROME_DATE_RE, ParseChromeDate, lambda m: m.group(1))
+    Pattern(CHROME_DATE_NEW_RE, ParseDate, lambda m: m.group(1)),
+    Pattern(CHROME_DATE_OLD_RE, ParseChromeDate, lambda m: m.group(1)),
 ]
 
 # 2017/07/31 09:18:08.871 DEBUG|     remote_access:0659| The temporary working directory on the device is /mnt/stateful_partition/unencrypted/preserve/cros-update/tmp.S7y5vF3xQE
 CROS_DATE_RE = re.compile(r'^(\d\d\d\d/\d\d/\d\d \d\d:\d\d:\d\d.\d\d\d) ')
 CrOSPatterns = [Pattern(CROS_DATE_RE, ParseDate, lambda m: m.group(1))]
 
-# [0731/070232:INFO:main.cc(289)] System uptime: 5s
-POWERD_DATE_RE = re.compile(r'^\[(\d{4}/\d{6}):')
+# 2021-01-27T05:38:56.751227Z INFO powerd: [main.cc(289)] System uptime: 5s
+POWERD_DATE_NEW_RE = re.compile(
+    r'^(\d\d\d\d-\d\d-\d\dT\d\d:\d\d:\d\d.\d\d\d\d\d\dZ) ')
+
+# [0127/053856:INFO:main.cc(289)] System uptime: 5s
+POWERD_DATE_OLD_RE = re.compile(r'^\[(\d{4}/\d{6}):')
+
 PowerdPatterns = [
-    Pattern(POWERD_DATE_RE, ParsePowerdDate, lambda m: m.group(1))
+    Pattern(POWERD_DATE_NEW_RE, ParseDate, lambda m: m.group(1)),
+    Pattern(POWERD_DATE_OLD_RE, ParsePowerdDate, lambda m: m.group(1)),
 ]
 
 # 2017-07-31 07:00:46,650 - DEBUG - Running hook: /usr/local/bin/hooks/check_ethernet.hook
diff --git a/scripts/merge_logs_unittest.py b/scripts/merge_logs_unittest.py
index 8c0590f..bbda0b5 100644
--- a/scripts/merge_logs_unittest.py
+++ b/scripts/merge_logs_unittest.py
@@ -94,8 +94,8 @@
                                            TZOFFSET))
 
 
-class ParseFileContentsTest(cros_test_lib.TestCase):
-  """Test that ParseFileContents behaves correctly."""
+class ParseFileContentsTest(ParseDateTestBase):
+  """Test that parsers can parse old and new log formats."""
 
   def testParseSysinfoPatterns(self):
     filename = 'messages'
@@ -104,13 +104,59 @@
 
     logs = merge_logs.ParseFileContents(filename, content)
     lines = content.splitlines()
+    expected_logs = [
+        merge_logs.Log(
+            filename=filename,
+            date=datetime.datetime(2017, 7, 31, 7, 5, 10, 257860, TZOFFSET),
+            log=lines[0]),
+        merge_logs.Log(
+            filename=filename,
+            date=datetime.datetime(2017, 7, 31, 7, 5, 10, 257860,
+                                   dateutil.tz.tzutc()),
+            log=lines[1])
+    ]
 
-    self.assertEqual(len(logs), 2)
-    self.assertEqual(logs[0].filename, filename)
-    self.assertEqual(logs[0].date,
-                     datetime.datetime(2017, 7, 31, 7, 5, 10, 257860, TZOFFSET))
-    self.assertEqual(logs[0].log, lines[0])
-    self.assertEqual(
-        logs[1].date,
-        datetime.datetime(2017, 7, 31, 7, 5, 10, 257860, dateutil.tz.tzutc()))
-    self.assertEqual(logs[1].log, lines[1])
+    self.assertCountEqual(logs, expected_logs)
+
+  def testParseChromePatterns(self):
+    filename = 'ui.LATEST'
+    content = """[1694:1694:0731/072833.409065:VERBOSE1:main.cc(480)] Error
+2017-01-27T05:34:14.464052Z ERROR chrome[1694:1694]: [main.cc(11)] Error"""
+
+    logs = merge_logs.ParseFileContents(filename, content)
+    lines = content.splitlines()
+    expected_logs = [
+        merge_logs.Log(
+            filename=filename,
+            date=datetime.datetime(2017, 7, 31, 7, 28, 33, 409065, TZOFFSET),
+            log=lines[0]),
+        merge_logs.Log(
+            filename=filename,
+            date=datetime.datetime(2017, 1, 27, 5, 34, 14, 464052,
+                                   dateutil.tz.tzutc()),
+            log=lines[1])
+    ]
+
+    self.assertCountEqual(logs, expected_logs)
+
+  def testParsePowerdPatterns(self):
+    filename = 'powerd.LATEST'
+    content = """[0731/070232:INFO:main.cc(289)] System uptime: 5s
+2017-01-27T05:34:14.464052Z INFO powerd: [main.cc(289)] System uptime: 5s"""
+
+    logs = merge_logs.ParseFileContents(filename, content)
+
+    lines = content.splitlines()
+    expected_logs = [
+        merge_logs.Log(
+            filename=filename,
+            date=datetime.datetime(2017, 7, 31, 7, 2, 32, 0, TZOFFSET),
+            log=lines[0]),
+        merge_logs.Log(
+            filename=filename,
+            date=datetime.datetime(2017, 1, 27, 5, 34, 14, 464052,
+                                   dateutil.tz.tzutc()),
+            log=lines[1])
+    ]
+
+    self.assertCountEqual(logs, expected_logs)