diff --git a/requirements/constraints.txt b/requirements/constraints.txt
index 6f96fdfff892..fe8566ca6628 100644
--- a/requirements/constraints.txt
+++ b/requirements/constraints.txt
@@ -48,8 +48,6 @@ django-oauth-toolkit<=1.3.2
 # ARCHBOM-1141: pip-tools upgrade requires pip upgrade
 pip-tools<6.0
 
-# Upgrading to 2.5.3 on 2020-01-03 triggered "'tzlocal' object has no attribute '_std_offset'" errors in production
-python-dateutil==2.4.0
 # matplotlib>=3.4.0 requires python-dateutil>=2.7
 matplotlib<3.4.0
 
diff --git a/requirements/edx-sandbox/py35.txt b/requirements/edx-sandbox/py35.txt
index a4abaf76fc93..d7b87b7d875f 100644
--- a/requirements/edx-sandbox/py35.txt
+++ b/requirements/edx-sandbox/py35.txt
@@ -62,7 +62,6 @@ numpy==1.16.5
     #   chem
     #   matplotlib
     #   openedx-calc
-    #   scipy
 openedx-calc==1.0.9
     # via -r requirements/edx-sandbox/py35.in
 pycparser==2.20
@@ -74,9 +73,7 @@ pyparsing==2.2.0
     #   matplotlib
     #   openedx-calc
 python-dateutil==2.4.0
-    # via
-    #   -c requirements/edx-sandbox/../constraints.txt
-    #   matplotlib
+    # via matplotlib
 pytz==2021.1
     # via matplotlib
 random2==1.0.1
diff --git a/requirements/edx-sandbox/py38.txt b/requirements/edx-sandbox/py38.txt
index 0fb2d333627e..4f96ed860011 100644
--- a/requirements/edx-sandbox/py38.txt
+++ b/requirements/edx-sandbox/py38.txt
@@ -66,9 +66,7 @@ pyparsing==2.4.7
     #   matplotlib
     #   openedx-calc
 python-dateutil==2.4.0
-    # via
-    #   -c requirements/edx-sandbox/../constraints.txt
-    #   matplotlib
+    # via matplotlib
 random2==1.0.1
     # via -r requirements/edx-sandbox/py38.in
 regex==2021.4.4
diff --git a/requirements/edx/base.txt b/requirements/edx/base.txt
index e4decb38c254..22a7e59f8b52 100644
--- a/requirements/edx/base.txt
+++ b/requirements/edx/base.txt
@@ -763,9 +763,8 @@ pysrt==1.1.2
     # via
     #   -r requirements/edx/base.in
     #   edxval
-python-dateutil==2.4.0
+python-dateutil==2.8.1
     # via
-    #   -c requirements/edx/../constraints.txt
     #   -r requirements/edx/base.in
     #   analytics-python
     #   botocore
diff --git a/requirements/edx/development.txt b/requirements/edx/development.txt
index 623d217fd5e7..d7b8ea3fe7ac 100644
--- a/requirements/edx/development.txt
+++ b/requirements/edx/development.txt
@@ -1065,9 +1065,8 @@ pytest==6.2.4
     #   pytest-metadata
     #   pytest-randomly
     #   pytest-xdist
-python-dateutil==2.4.0
+python-dateutil==2.8.1
     # via
-    #   -c requirements/edx/../constraints.txt
     #   -r requirements/edx/testing.txt
     #   analytics-python
     #   botocore
diff --git a/requirements/edx/testing.txt b/requirements/edx/testing.txt
index 79b3111aa2f4..cb725eff24cc 100644
--- a/requirements/edx/testing.txt
+++ b/requirements/edx/testing.txt
@@ -1006,9 +1006,8 @@ pytest==6.2.4
     #   pytest-metadata
     #   pytest-randomly
     #   pytest-xdist
-python-dateutil==2.4.0
+python-dateutil==2.8.1
     # via
-    #   -c requirements/edx/../constraints.txt
     #   -r requirements/edx/base.txt
     #   analytics-python
     #   botocore