No it is not a simile because it does not use the term like or as in its description. Were you to say patience is like an hourglass it would be a simile. The way you worded it makes it a metaphor.
A simile.
A metaphor
As quick as a wink is a simile. ----
It is a simile.
The hourglass dolphin is called an hourglass dolphin because its black and white markings resemble an hourglass!
simile It is an example of a simile (uses like or as). A simile in itself though is a type of metaphor.
simile
An hourglass was used as a timer, with the size of the hourglass determining the length of time it measured.
that man
It is a similie as you are comparing (something) to how sly the fox is. A similie uses the words "like or "as".
How many seconds are in a hourglass
glass+sand=hourglass