Historical clue formulations

• Neighbor of Sierra Leone — 2026-09-04
• ___ pig — 2023-01-01
• ___ pig — 2014-04-08
• Old British coin — 2004-09-12
• Former British money — 2001-07-22
• Kind of pig — 1999-09-14
• 21 shillings — 1996-05-22
• Equivalent of 21 shillings — 1995-09-06