Adjust the Docker publish to include a date/time tag as well for the weekly push.

.github/workflows/docker.yml

@@ -12,16 +12,16 @@ jobs:
     steps:
       - name: Check out the repo
         uses: actions/checkout@v2
-      -
-        name: Login to Docker Hub
+      - name: Login to Docker Hub
         uses: docker/login-action@v1
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_PASSWORD }}
-      
+      - name: Get current date/time in the usual format to set the tags
+        run: echo "DATE_TIME=$(date + '%Y.%m.%d.%H%M%S')" >> $GITHUB_ENV
       - name: Build and push Docker image
         uses: docker/build-push-action@v2
         with:
           context: .
           push: true
-          tags: mikeah/prusaslicer-novnc:latest
+          tags: mikeah/prusaslicer-novnc:latest, mikeah/prusaslicer-novnc:${{ env.DATE_TIME }}