ArcGIS Pro 2.1, attribute rule, calculation contains this expression:
Text(Now(), 'ddd D MMM Y')
This gets inserted into the features attribute table, text field:
Wed 28 Feb Y
I also tried this expression:
Text(Now(), 'ddd D MMM yyyy')
This was the result:
Wed 28 Feb yyyy
Here's the workaround (messy):
var fir = Text(Now(), 'ddd D MMM');
var sec = Text(Year(Now()));
var arr = [fir,sec];
return Concatenate(arr,' ')