Possible Clues:

• Too soon to have been beheaded every so often
• Periodical too wise, we hear, to admit a nobleman
• At last ferry's in good time - not such a frequent event!
• Every so often it comes too soon at last
• For 32 across it's too soon to be beheaded
• It's too soon to have taken off the top of this, every so often
• How 20 down at last comes from time to time
• At annual intervals
• Youth leader meets prior every twelvemonth
• Like Santa's visit