datestuff

README.md

@@ -12,6 +12,8 @@ persistence.
 - Item locking mechanism to prevent conflicts
 - Hierarchical items (parent-child relationships)
 - **Item dependencies: Define prerequisites for completing items**
+- **Date constraints: Set "not before" and "not after" times for item
+  completion**
 - SQLite database for data persistence
 - **Modern web frontend with React and TypeScript**
 - **Real-time updates across multiple browser tabs/windows**
@@ -295,7 +297,9 @@ All API endpoints return JSON responses with a consistent format:
       "checked": false,
       "parent_id": null,
       "checklist_uuid": "123e4567-e89b-12d3-a456-426614174000",
-      "dependencies": []
+      "dependencies": [],
+      "not_before": "2025-07-25T16:20:00Z",
+      "not_after": "2025-07-25T18:00:00Z"
    }
 }
 ```
@@ -312,7 +316,9 @@ All API endpoints return JSON responses with a consistent format:
       "checked": true,
       "parent_id": null,
       "checklist_uuid": "123e4567-e89b-12d3-a456-426614174000",
-      "dependencies": [2, 3]
+      "dependencies": [2, 3],
+      "not_before": "2025-07-25T16:20:00Z",
+      "not_after": "2025-07-25T18:00:00Z"
    }
 }
 ```
@@ -352,7 +358,9 @@ All API endpoints return JSON responses with a consistent format:
          "checked": false,
          "parent_id": null,
          "checklist_uuid": "123e4567-e89b-12d3-a456-426614174000",
-         "dependencies": []
+         "dependencies": [],
+         "not_before": null,
+         "not_after": null
       },
       {
          "id": 2,
@@ -360,7 +368,9 @@ All API endpoints return JSON responses with a consistent format:
          "checked": true,
          "parent_id": null,
          "checklist_uuid": "123e4567-e89b-12d3-a456-426614174000",
-         "dependencies": [1]
+         "dependencies": [1],
+         "not_before": "2025-07-25T16:20:00Z",
+         "not_after": null
       }
    ]
 }
@@ -376,7 +386,8 @@ All API endpoints return JSON responses with a consistent format:
 The application uses SQLite with the following schema:
 
 - `checklist_info` table: Stores checklist metadata (uuid, name)
-- `items` table: Stores checklist items with hierarchical relationships
+- `items` table: Stores checklist items with hierarchical relationships and date
+  constraints
 - `dependencies` table: Stores item dependencies (item_id, dependency_id)
 
 ## Real-time Features
@@ -422,6 +433,47 @@ that must be completed before an item can be marked as done.
 - **Clear Feedback**: Users see exactly which items need to be completed first
 - **Error Prevention**: System prevents circular dependencies automatically
 
+## Item Date Constraints
+
+The application supports date constraints, allowing you to set time windows when
+items can be completed.
+
+### How Date Constraints Work
+
+- **Not Before**: Set the earliest time an item can be completed
+- **Not After**: Set the latest time an item can be completed
+- **Validation**: Items cannot be completed outside their allowed time window
+- **Visual Indicators**: Items show date constraint status with color-coded
+  indicators
+- **Real-time Updates**: Constraint status updates in real-time
+
+### Managing Date Constraints
+
+1. **Set Constraints**: Click the clock icon (🕐) on any item to open the date
+   constraint manager
+2. **Configure Times**: Set "not before" and/or "not after" times
+3. **Visual Feedback**: Items show constraint status:
+   - 🟢 Green: Time constraints met (shows "Ready")
+   - 🔴 Red: Time constraints not met (shows "Time locked")
+4. **Completion Prevention**: Items cannot be checked off outside their time
+   window
+
+### Date Constraint Features
+
+- **Flexible Scheduling**: Set any combination of start and end times
+- **ISO 8601 Format**: Uses standard datetime format for precision
+- **Real-time Validation**: Constraint status updates immediately
+- **Clear Feedback**: Users see exactly when items can be completed
+- **Error Prevention**: System prevents completion outside allowed times
+
+### Example Use Cases
+
+- **Meeting Preparation**: Set items to be completed before a meeting starts
+- **Deadline Management**: Set items to be completed by a specific deadline
+- **Time-sensitive Tasks**: Ensure tasks are completed within business hours
+- **Sequential Workflows**: Use in combination with dependencies for complex
+  workflows
+
 ## Development
 
 ### Local Development