diff --git a/CHANGES.md b/CHANGES.md
index f46548e..a2defda 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,6 +6,7 @@
 * Update cachecontrol library 0.12.4 (bd94f7e) to 0.12.5 (007e8ca)
 * Update Certifi 2019.03.09 (401100f) to 2019.06.16 (84dc766)
 * Update ConfigObj 5.1.0 (a68530a) to 5.1.0 (45fbf1b)
+* Update dateutil 2.8.0 (c90a30c) to 2.8.0 (27848c5)
 * Update DiskCache library 3.1.1 (2649ac9) to 4.0.0 (2c79bb9)
 * Update feedparser 5.2.1 (2b11c80) to 5.2.1 (cbe18d0)
 * Update Fuzzywuzzy 0.15.1 to 0.17.0 (778162c)
diff --git a/lib/dateutil/parser/_parser.py b/lib/dateutil/parser/_parser.py
index 9b5e7eb..24c5e10 100644
--- a/lib/dateutil/parser/_parser.py
+++ b/lib/dateutil/parser/_parser.py
@@ -423,7 +423,7 @@ class _ymd(list):
         elif not self.has_month:
             return 1 <= value <= 31
         elif not self.has_year:
-            # Be permissive, assume leapyear
+            # Be permissive, assume leap year
             month = self[self.mstridx]
             return 1 <= value <= monthrange(2000, month)[1]
         else:
@@ -539,7 +539,7 @@ class _ymd(list):
                     year, month, day = self
                 else:
                     # 01-Jan-01
-                    # Give precendence to day-first, since
+                    # Give precedence to day-first, since
                     # two-digit years is usually hand-written.
                     day, month, year = self
 
@@ -1025,7 +1025,7 @@ class parser(object):
             hms_idx = idx + 2
 
         elif idx > 0 and info.hms(tokens[idx-1]) is not None:
-            # There is a "h", "m", or "s" preceeding this token.  Since neither
+            # There is a "h", "m", or "s" preceding this token.  Since neither
             # of the previous cases was hit, there is no label following this
             # token, so we use the previous label.
             # e.g. the "04" in "12h04"
@@ -1105,7 +1105,7 @@ class parser(object):
     def _parse_min_sec(self, value):
         # TODO: Every usage of this function sets res.second to the return
         # value. Are there any cases where second will be returned as None and
-        # we *dont* want to set res.second = None?
+        # we *don't* want to set res.second = None?
         minute = int(value)
         second = None
 
diff --git a/lib/dateutil/relativedelta.py b/lib/dateutil/relativedelta.py
index ec7f66d..fa7f649 100644
--- a/lib/dateutil/relativedelta.py
+++ b/lib/dateutil/relativedelta.py
@@ -45,7 +45,7 @@ class relativedelta(object):
         years, months, weeks, days, hours, minutes, seconds, microseconds:
             Relative information, may be negative (argument is plural); adding
             or subtracting a relativedelta with relative information performs
-            the corresponding aritmetic operation on the original datetime value
+            the corresponding arithmetic operation on the original datetime value
             with the information in the relativedelta.
 
         weekday: 
diff --git a/lib/dateutil/rrule.py b/lib/dateutil/rrule.py
index 7b54539..c774c8f 100644
--- a/lib/dateutil/rrule.py
+++ b/lib/dateutil/rrule.py
@@ -177,7 +177,7 @@ class rrulebase(object):
                     return False
         return False
 
-    # __len__() introduces a large performance penality.
+    # __len__() introduces a large performance penalty.
     def count(self):
         """ Returns the number of recurrences in this set. It will have go
             trough the whole recurrence, if this hasn't been done before. """
diff --git a/lib/dateutil/tz/_common.py b/lib/dateutil/tz/_common.py
index 5f15e9a..9933257 100644
--- a/lib/dateutil/tz/_common.py
+++ b/lib/dateutil/tz/_common.py
@@ -212,7 +212,7 @@ class _tzinfo(tzinfo):
         Since this is the one time that we *know* we have an unambiguous
         datetime object, we take this opportunity to determine whether the
         datetime is ambiguous and in a "fold" state (e.g. if it's the first
-        occurence, chronologically, of the ambiguous datetime).
+        occurrence, chronologically, of the ambiguous datetime).
 
         :param dt:
             A timezone-aware :class:`datetime.datetime` object.
@@ -250,7 +250,7 @@ class _tzinfo(tzinfo):
         Since this is the one time that we *know* we have an unambiguous
         datetime object, we take this opportunity to determine whether the
         datetime is ambiguous and in a "fold" state (e.g. if it's the first
-        occurance, chronologically, of the ambiguous datetime).
+        occurrence, chronologically, of the ambiguous datetime).
 
         :param dt:
             A timezone-aware :class:`datetime.datetime` object.
diff --git a/lib/dateutil/tz/tz.py b/lib/dateutil/tz/tz.py
index 5aa7e5d..8f51ee3 100644
--- a/lib/dateutil/tz/tz.py
+++ b/lib/dateutil/tz/tz.py
@@ -385,7 +385,7 @@ class _tzfile(object):
 
 class tzfile(_tzinfo):
     """
-    This is a ``tzinfo`` subclass thant allows one to use the ``tzfile(5)``
+    This is a ``tzinfo`` subclass that allows one to use the ``tzfile(5)``
     format timezone files to extract current and historical zone information.
 
     :param fileobj:
@@ -1827,7 +1827,7 @@ else:
 
 try:
     # Python 3.7 feature
-    from contextmanager import nullcontext as _nullcontext
+    from contextlib import nullcontext as _nullcontext
 except ImportError:
     class _nullcontext(object):
         """
diff --git a/lib/dateutil/utils.py b/lib/dateutil/utils.py
index 12bb045..cae8fc7 100644
--- a/lib/dateutil/utils.py
+++ b/lib/dateutil/utils.py
@@ -28,7 +28,7 @@ def today(tzinfo=None):
 
 def default_tzinfo(dt, tzinfo):
     """
-    Sets the the ``tzinfo`` parameter on naive datetimes only
+    Sets the ``tzinfo`` parameter on naive datetimes only
 
     This is useful for example when you are provided a datetime that may have
     either an implicit or explicit time zone, such as when parsing a time zone