Refactor: Remove magic number from constraint DayMonthYear
Refactor: Remove magic number from constraint DayMonthYear

Former-commit-id: aad5d6da5f9a8e2123c6b0297872a1d48f0efa24
dvla/vehicles-online,dvla/vrm-retention-online,dvla/vehicles-online,dvla/vehicles-presentation-common,dvla/vehicles-online,dvla/vrm-retention-online,dvla/vehicles-online,dvla/vrm-retention-online,dvla/vrm-retention-online,dvla/vehicles-presentation-common,dvla/vehicles-presentation-common