diff --git a/requirements/constraints.txt b/requirements/constraints.txt
index 1de3082f75..a5a5f8785e 100644
--- a/requirements/constraints.txt
+++ b/requirements/constraints.txt
@@ -52,15 +52,15 @@ mysqlclient<1.5
 requests-oauthlib==1.1.0
 oauthlib==2.1.0
 
+# Version 0.23.0 requires python-dateuil>=2.5.0
+pandas==0.22.0
+
+# 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
+
 # python3-saml 1.6.0 breaks unittests in common/djangoapps/third_party_auth/tests/test_views.py::SAMLMetadataTest
 python3-saml==1.5.0
 
 # transifex-client 0.13.5 and 0.13.6 pin six and urllib3 to old versions needlessly
 #   https://github.com/transifex/transifex-client/issues/252
 transifex-client==0.13.4
-
-# moving constraint from base.in to constraints.txt
-python-dateutil<2.6.0
-
-#higher releases require python>3.5
-pandas<0.25.0
diff --git a/requirements/edx-sandbox/py35.in b/requirements/edx-sandbox/py35.in
index 045d546aec..1a2ed69a87 100644
--- a/requirements/edx-sandbox/py35.in
+++ b/requirements/edx-sandbox/py35.in
@@ -7,8 +7,6 @@
 #   * confirm that it has no system requirements beyond what we already install
 #   * run "make upgrade" to update the detailed requirements files
 
--c ../constraints.txt
-
 -r shared.txt                       # Dependencies in common with LMS and Studio
 matplotlib==2.2.4                   # 2D plotting library
 networkx==2.2                       # Utilities for creating, manipulating, and studying network graphs
diff --git a/requirements/edx-sandbox/py35.txt b/requirements/edx-sandbox/py35.txt
index 3db7b19f5d..458f9b2e50 100644
--- a/requirements/edx-sandbox/py35.txt
+++ b/requirements/edx-sandbox/py35.txt
@@ -22,7 +22,7 @@ nltk==3.4.5
 numpy==1.16.5
 pycparser==2.19
 pyparsing==2.2.0
-python-dateutil==2.5.3    # via matplotlib
+python-dateutil==2.8.1    # via matplotlib
 pytz==2019.3              # via matplotlib
 random2==1.0.1
 scipy==1.2.1
diff --git a/requirements/edx/base.txt b/requirements/edx/base.txt
index ebd3083c9d..daabbdc76b 100644
--- a/requirements/edx/base.txt
+++ b/requirements/edx/base.txt
@@ -192,7 +192,7 @@ pymongo==3.9.0
 pynliner==0.8.0
 pyparsing==2.2.0          # via pycontracts
 pysrt==1.1.1
-python-dateutil==2.5.3
+python-dateutil==2.4.0
 python-levenshtein==0.12.0
 python-memcached==1.59
 python-slugify==4.0.0     # via code-annotations
diff --git a/requirements/edx/coverage.txt b/requirements/edx/coverage.txt
index f7208d6497..d92ee22665 100644
--- a/requirements/edx/coverage.txt
+++ b/requirements/edx/coverage.txt
@@ -13,10 +13,10 @@ jinja2==2.10.3            # via diff-cover, jinja2-pluralize
 markupsafe==1.1.1         # via jinja2
 more-itertools==8.0.2     # via zipp
 numpy==1.18.0             # via pandas
-pandas==0.24.2
+pandas==0.22.0
 pluggy==0.13.1            # via diff-cover
 pygments==2.5.2           # via diff-cover
-python-dateutil==2.5.3    # via pandas
+python-dateutil==2.4.0    # via pandas
 pytz==2019.3              # via pandas
 six==1.13.0               # via diff-cover
 zipp==0.6.0               # via importlib-metadata
diff --git a/requirements/edx/development.txt b/requirements/edx/development.txt
index cda9e58b8e..2bafd2c2aa 100644
--- a/requirements/edx/development.txt
+++ b/requirements/edx/development.txt
@@ -209,7 +209,7 @@ git+https://github.com/joestump/python-oauth2.git@b94f69b1ad195513547924e380d926
 oauthlib==2.1.0
 git+https://github.com/edx/edx-ora2.git@2.5.4#egg=ora2==2.5.4
 packaging==19.2
-pandas==0.24.2
+pandas==0.22.0
 path.py==8.2.1
 pathlib2==2.3.5
 pathtools==0.1.2
@@ -256,7 +256,7 @@ pytest-metadata==1.8.0
 pytest-randomly==3.2.0
 pytest-xdist==1.31.0
 pytest==5.3.2
-python-dateutil==2.5.3
+python-dateutil==2.4.0
 python-levenshtein==0.12.0
 python-memcached==1.59
 python-slugify==4.0.0
diff --git a/requirements/edx/testing.txt b/requirements/edx/testing.txt
index b5fc5f56fe..a93f9746c9 100644
--- a/requirements/edx/testing.txt
+++ b/requirements/edx/testing.txt
@@ -201,7 +201,7 @@ git+https://github.com/joestump/python-oauth2.git@b94f69b1ad195513547924e380d926
 oauthlib==2.1.0
 git+https://github.com/edx/edx-ora2.git@2.5.4#egg=ora2==2.5.4
 packaging==19.2           # via pytest, tox
-pandas==0.24.2
+pandas==0.22.0
 path.py==8.2.1
 pathlib2==2.3.5           # via pytest
 pathtools==0.1.2
@@ -245,7 +245,7 @@ pytest-metadata==1.8.0    # via pytest-json-report
 pytest-randomly==3.2.0
 pytest-xdist==1.31.0
 pytest==5.3.2
-python-dateutil==2.5.3
+python-dateutil==2.4.0
 python-levenshtein==0.12.0
 python-memcached==1.59
 python-slugify==4.0.0