The data formatting of a date is not considered a style. I recommend posting this suggestion to the Product Ideas board at: Product Ideas
The Product Ideas board is monitored by Product Management and Development. All entries are discussed and considered for possible implementation in a future release.
well... since we can't have our date format, I consider this as a bug - why entering a feature request for a bug?
Perform the following steps:
1. Create a Date field.
2. Format the Date field for 18 Point, Text Color Red, Bold, a set the Data formatting to Thursday, December 25, 2014.
3. Save the Style as "Date" and apply it to the Theme.
4. Go to Browse mode and enter today's date. It will display something similar to "Thursday, April 27, 2016".
4. Create a new layout with the same theme.
5. Add the Date field to the layout.
6. Apply the style "Date". The field will show 18 Point, Text Color Red and Bold.
7. Go to Browse. The contents do not show the Data Formatting.