Here are ten tools, libraries, approaches, and SaaS products that allow visualization of time-based DynamoDB data in a dashboard:

1. Amazon QuickSight: Amazon's cloud-based business intelligence (BI) service that enables you to create interactive dashboards and visualizations. It natively supports connecting to DynamoDB and can visualize time-based data.

2. Kibana: An open-source data visualization and exploration tool that is commonly used as part of the Elastic Stack (formerly known as the ELK Stack). Kibana can connect to DynamoDB using the Logstash plugin and visualize time-based data in various charts and dashboards.

3. Grafana: An open-source platform for monitoring and observability that allows you to create dashboards and visualize data from various sources, including DynamoDB. Grafana has a DynamoDB plugin that enables querying and visualizing time-based data.

4. AWS Glue and Amazon Athena: AWS Glue is a fully managed ETL (extract, transform, and load) service that can be used to extract data from DynamoDB and store it in Amazon S3. Amazon Athena, a serverless query service, can then be used to query the data and visualize it using tools like Amazon QuickSight or Tableau.

5. AWS Lambda and Amazon API Gateway: You can use AWS Lambda functions to retrieve time-based data from DynamoDB and expose the data through APIs created with Amazon API Gateway. The data can then be consumed by frontend frameworks or libraries to create custom dashboards.

6. Chart.js: A popular open-source JavaScript library for creating interactive and responsive charts. You can fetch time-based data from DynamoDB using AWS SDK or API calls and visualize it using Chart.js in a web-based dashboard.

7. D3.js: A powerful JavaScript library for creating data-driven visualizations. Similar to Chart.js, you can retrieve time-based data from DynamoDB and use D3.js to create custom visualizations and dashboards.

8. Tableau: A widely used business intelligence and data visualization tool. Tableau can connect to DynamoDB and create interactive dashboards and visualizations based on time-based data.

9. Looker: A cloud-based BI and data analytics platform that allows you to explore and visualize data from various sources, including DynamoDB. Looker supports connecting to DynamoDB and creating dashboards with time-based data.

10. Retool: A low-code platform for building custom internal tools and dashboards. Retool provides pre-built components and connectors, including a DynamoDB connector, which enables you to query and visualize time-based data in a drag-and-drop interface.

These are just a few examples, and the choice of tool or approach depends on your specific requirements, technical skills, and the scale of your DynamoDB data. You can choose the option that best fits your needs and integrates well with your existing infrastructure and development stack.