You can log on to the volunteer service platform of Harbin Institute of Technology to inquire about the volunteer duration. The specific steps are as follows:

1. Enter official website, the volunteer service platform of Harbin Institute of Technology.

2. Click the "Login" button in the upper right corner of the webpage and log in with the student ID and password.

3. After logging in, click the "Volunteer Service" option in the navigation bar at the top of the home page to enter the exclusive volunteer service page.

4. In the menu bar on the left side of the page, select "My Volunteer" to query your volunteer time and volunteer record.

5. If you need to query the volunteer duration in a certain period of time, you can select "Volunteer Duration Management" in the left menu bar, and select the query date and service type as needed to query the volunteer duration in a specified period of time.