Painting time as a concept is very difficult. Once solution is to show the Fates, as depicted by Rubens, Goya, Burne-Jones, Jacek Malczewski and others.
Thumann
From Aphrodite to Vesta, a reference summary of all the major Classical goddesses, with links to individual accounts.
Epitomising human attitudes to life and death for millennia, they spin the thread of life, measure the length allotted to each person, and cut that length with shears.
The Eclectic Light Company 