diff --git a/.github/workflows/osx.yml b/.github/workflows/osx.yml
index 196c41d6..35f2816d 100644
--- a/.github/workflows/osx.yml
+++ b/.github/workflows/osx.yml
@@ -37,6 +37,14 @@ jobs:
       run: |
         echo "  - clangxx==17.0.6" >> environment-dev.yml
 
+    - name: Add `howardhinnant_date` in the conda environment specification
+      run: |
+        # P0355R7 (Extending chrono to Calendars and Time Zones) has not been entirely implemented in libc++ yet.
+        # See: https://libcxx.llvm.org/Status/Cxx20.html#note-p0355
+        # For now, we use HowardHinnant/date as a replacement if we are compiling with libc++.
+        # TODO: remove this once libc++ has full support for P0355R7.
+        echo "  - howardhinnant_date" >> environment-dev.yml
+
     - name: Set conda environment
       uses: mamba-org/setup-micromamba@main
       with:
diff --git a/environment-dev.yml b/environment-dev.yml
index 8e988926..19e8c1d0 100644
--- a/environment-dev.yml
+++ b/environment-dev.yml
@@ -5,7 +5,5 @@ dependencies:
   # Build
   - cmake
   - ninja
-  # Alternative of `std::chrono` introduced in C++20.
-  - howardhinnant_date
   # Tests
   - doctest