Related Clues:

• '___ again ...'
• In times past
• In history
• ___-walsy
• That time
• Proust novel "Remembrance of Things ---"
• Perfect start?
• Historian's interest
• What olden days were of
• Time machine's destination
• Bygone period
• One of the ghosts of 34-Across
• Bygone times
• Future's opposite
• Past time