The code you started with has no day code.
{QUOTE {SET Delay 1} {DATE \@ MMMM}160{={DATE \@ yyyy}+Delay}}

Try instead:
{QUOTE {SET Delay 1} {DATE \@ "d/MMMM/"}{={DATE \@ yyyy}+Delay}}

Since you are editing the DATE field, when you toggle it back to results, those results are not changed until the field is updated. That is why both of us have told you that you need to press the F9 key to update the field.

Yes, Ctrl+F9 lets you insert a blank field to type in.