Death keeps no calendar

Possible interpretation: In this saying, "Death" is personified as a spiritual being who may call upon us at any time - he has no appointment book. We never know when we will die.

Note: Death (noun) = personification of the force that destroys life | death (noun) = the act of dying; the end of life | calendar (noun) = chart showing the days, weeks and months of each year; diary; datebook