Unity of time
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
One of the essential properties of a joint estate; the estates of the tenants being vested at one and the same period. 2 Bl. Comm. 181.
— Unity of title. applied to joint tenants, to signify that they hold their property by one and the same title, while tenants in common may take property by several titles. Williams, Reai Prop. 134.
Defined under Unity in Black's Law Dictionary.