In Shakespeare’s day there were three ways of measuring time: hourglasses, sundials and clocks. Shakespeare, who refers to each, seems to have thought of time differently depending on the instrument he imagined measuring it.

Hourglasses

Sometimes Shakespeare writes of time in terms of an hourglass: an instrument made from two conical glass bulbs joined at the middle and filled with ‘sand’ – actually, iron filings, powdered eggshell or marble dust.

When, in Pericles, Gower the narrator says ‘our sands are almost run’ (5.2.1), he means the sand in the hourglass has almost run through, and that the play is almost over.

These days when we talk about ‘running out of time’, we are still using the vocabulary of the hourglass in which time always appears to be hurrying.

Sundials

Sometimes Shakespeare thinks of time as it appears on a sundial: a plate marked with the hours onto which a pointer cast a shadow when the sun shone.

On a sundial, time was relayed from the sky – perhaps from God itself.

It was, however, only revealed when the sun shone, and only visible through shadows; so when Shakespeare remarks that ‘Thou by thy dial’s shady stealth may’st know, / Time’s thievish progress to eternity’ (Sonnet 77) he is writing about secretive sundial time.