Perpetual Calendar Chronograph

Family timeline

10 references in production order. Overlapping bars show overlapping recorded dates.

• 3970EP-0191987–2004
• 3970EP-0211987–2004
• 3970Ec. 1990–c. 1998
• 3970ERc. 1990–?
• 3970Jc. 1991–c. 1992
• 3970EPc. 1993–?
• 3970Pc. 2000–?
• 3970EGUndatedUndated — position unknown
• 5004RUndatedUndated — position unknown
• 5020RUndatedUndated — position unknown

Dates are those recorded in the catalog. Faint bars mark approximate dates; a dashed point marks a single known endpoint. Undated references remain visible. Chronological order does not establish a predecessor or successor relationship.