Revamped resettled yard for memorably happy occasions (3-6,4)

I believe the answer is:

red-letter days

I'm a little stuck... Click here to teach me more about this clue!

'memorably happy occasions' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'revamped resettled yard' is the wordplay.
'revamped' is an anagram indicator.
'resettled'+'yard'='resettledyard'
'resettledyard' is an anagram of 'RED-LETTER DAYS'.

'for' acts as a link.

Can you help me to learn more?

(Another definition for red-letter days that I've seen is " Noteworthy dates".)

I've seen this clue in The Irish Times.

Want a hint initially instead of a full solution? Install my app