Expression "you are ancient of days"

[Sara_h]

HI,
I would like to know what the expression 'you are ancient of days' means.
Just to add, I've come across it while reading one poem and since then I can't find the meaning, although I've looked it up in many dictionaries. So , the only hope is your advice or any suggestion.

[Mister Micawber]

.
It is a stylized and euphuistic way of saying 'you are old'.
.
_________________
Canadian-American native speaker
who teaches English for a living at Mister Micawber's
ESL cafe: Interview with Mr. Micawber

[Sara_h]

Thank you a lot.