2. Click to select the table with the date of birth, click the right mouse button and select the "format cell" below.

3. In the Cell Formatting box, under Numbers, select Custom.

4. The number type selection bar appears on the right, and click enter "0". You can enter "0000-00-00" in the type box yourself, and you can see that the above date of birth format has changed.

5. After the modification is completed, click OK and use the mouse to select the modified table box.

6. Put the mouse in the lower right corner and an entity will appear. Click the drop-down box and select the tool below.

7. Click for the third time and select Fill Format Only.