Choose a template
Due Date → Due_x0020_Date). To keep it clean, create the column with no spaces (like DueDate), then rename the display label afterward if you want spaces. To check an existing column's internal name: edit the column and read the URL — the part after &Field= is it.
Show paste instructions
- Open your SharePoint list.
- Click the column header you want to format.
- Choose Column settings.
- Choose Format this column.
- Select Advanced mode (near the bottom of the pane).
- Delete what's in the box and paste this JSON.
- Click Preview, then Save.
If nothing changes, double-check that your internal field name matches the column.