https://trailhead.salesforce.com/en/content/learn/modules/nonprofit-success-pack-administration-basics/understand-the-npsp-data-model

For nonprofits needing to track key information related to grants, such as deadline dates, activity completion dates, and descriptions, Deliverables within Salesforce are the recommended feature. Deliverables allow nonprofits to create and manage detailed records of grant-related activities, set deadlines, and monitor progress directly on the Opportunity object.

Steps:

Enable Deliverables in Salesforce.

Create Deliverable records to track grant-related tasks, deadlines, and activities.

Configure Deliverables to display the next deadline date on the Opportunity.

Use reports and dashboards to monitor the status and progress of grant-related activities.