As a volunteer, the hours visible on your timesheet may be limited by your organization's settings. Some organizations may choose to reset hours for new reporting cycles and this will impact how you see previously approved hours. 

To view a comprehensive record of all hours in the system, you will need to export the data from your volunteer account. To do this, go to the main dashboard of your account and click Export All Hours. 

This will show all hours logged for your account, even if they are outside the current reporting cycle.