To create a GUI application in Python that fulfills your requirements, we will use the `tkinter` library for the GUI and `sqlite3` as the database to store the Day Book entries. Below is a complete example of how this can be implemented.
### Requirements:
1. Install `tkinter` (usually comes pre-installed with Python).
2. Install `sqlite3` (also comes with standard Python library).
### Complete Code:
```python
import tkinter as tk
from tkinter