diff --git a/docs/demo/scripts/oxford_demo.py b/docs/demo/scripts/oxford_demo.py
index c64c834..129ee18 100644
--- a/docs/demo/scripts/oxford_demo.py
+++ b/docs/demo/scripts/oxford_demo.py
@@ -123,7 +123,7 @@
 
 
 dates = input_data.date.unique()
-dates.sort()
+dates = dates[dates.argsort()]
 dates = [pd.Timestamp(x) for x in dates]
 print(dates[0:10])
 # %% [markdown]
diff --git a/pyproject.toml b/pyproject.toml
index 21f11e6..fee3524 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,7 +33,7 @@ dev = [
 ]
 
 demos = [
-    "pandas==1.5.2",
+    "pandas",
     "geopandas",
     "matplotlib",
     "shapely"
diff --git a/requirements-demos.txt b/requirements-demos.txt
index 11e8569..a1a72a5 100644
--- a/requirements-demos.txt
+++ b/requirements-demos.txt
@@ -23,7 +23,7 @@ colorama==0.4.6
     # via
     #   click
     #   tqdm
-contourpy==1.1.1
+contourpy==1.2.0
     # via matplotlib
 cycler==0.12.1
     # via matplotlib
@@ -31,7 +31,7 @@ dill==0.3.7
     # via wsimod (pyproject.toml)
 fiona==1.9.5
     # via geopandas
-fonttools==4.43.1
+fonttools==4.44.0
     # via matplotlib
 geopandas==0.14.0
     # via wsimod (pyproject.toml)
@@ -49,7 +49,7 @@ packaging==23.2
     # via
     #   geopandas
     #   matplotlib
-pandas==1.5.2
+pandas==2.1.2
     # via
     #   geopandas
     #   wsimod (pyproject.toml)
@@ -77,6 +77,8 @@ six==1.16.0
     #   python-dateutil
 tqdm==4.66.1
     # via wsimod (pyproject.toml)
+tzdata==2023.3
+    # via pandas
 
 # The following packages are considered to be unsafe in a requirements file:
 # setuptools
diff --git a/requirements-doc.txt b/requirements-doc.txt
index 704e929..4378cb2 100644
--- a/requirements-doc.txt
+++ b/requirements-doc.txt
@@ -42,9 +42,9 @@ colorama==0.4.6
     #   mkdocs
     #   mkdocs-material
     #   tqdm
-comm==0.1.4
+comm==0.2.0
     # via ipykernel
-contourpy==1.1.1
+contourpy==1.2.0
     # via matplotlib
 cycler==0.12.1
     # via matplotlib
@@ -64,7 +64,7 @@ fastjsonschema==2.18.1
     # via nbformat
 fiona==1.9.5
     # via geopandas
-fonttools==4.43.1
+fonttools==4.44.0
     # via matplotlib
 geopandas==0.14.0
     # via wsimod
@@ -90,7 +90,7 @@ jsonschema==4.19.2
     # via nbformat
 jsonschema-specifications==2023.7.1
     # via jsonschema
-jupyter-client==8.5.0
+jupyter-client==8.6.0
     # via
     #   ipykernel
     #   nbclient
@@ -159,7 +159,7 @@ mkdocs-coverage==1.0.0
     # via wsimod (pyproject.toml)
 mkdocs-jupyter==0.24.6
     # via wsimod (pyproject.toml)
-mkdocs-material==9.4.7
+mkdocs-material==9.4.8
     # via
     #   mkdocs-jupyter
     #   wsimod (pyproject.toml)
@@ -175,7 +175,7 @@ mkdocstrings-python==1.7.3
     # via mkdocstrings
 nbclient==0.8.0
     # via nbconvert
-nbconvert==7.10.0
+nbconvert==7.11.0
     # via mkdocs-jupyter
 nbformat==5.9.2
     # via
@@ -199,7 +199,7 @@ packaging==23.2
     #   nbconvert
 paginate==0.5.6
     # via mkdocs-material
-pandas==1.5.2
+pandas==2.1.2
     # via
     #   geopandas
     #   wsimod
@@ -276,7 +276,7 @@ requests==2.31.0
     # via
     #   mkdocs-bibtex
     #   mkdocs-material
-rpds-py==0.10.6
+rpds-py==0.12.0
     # via
     #   jsonschema
     #   referencing
@@ -319,6 +319,8 @@ traitlets==5.13.0
     #   nbclient
     #   nbconvert
     #   nbformat
+tzdata==2023.3
+    # via pandas
 urllib3==2.0.7
     # via requests
 validators==0.22.0
diff --git a/wsimod/demo/create_oxford.py b/wsimod/demo/create_oxford.py
index bd04bf0..80fc0db 100644
--- a/wsimod/demo/create_oxford.py
+++ b/wsimod/demo/create_oxford.py
@@ -168,7 +168,7 @@ def create_oxford_model(data_folder):
         .to_dict()
     )
     dates = input_data.date.unique()
-    dates.sort()
+    dates = dates[dates.argsort()]
     dates = [pd.Timestamp(x) for x in dates]
     constants.POLLUTANTS = input_data.variable.unique().tolist()
     constants.POLLUTANTS.remove("flow")