Understanding UNIX `time` command output

Bizarrely, I couldn’t find any documentation as to the output from the UNIX (BASH shell version 3.2.57(1)-release, here) `time` command. I thought I had it, but I wanted to be sure, so I wrote a quick shell script to verify my understanding. A script that takes 1 minute, 5 seconds to run will have output that looks something like this:

iMac:~ me$ cat time_test.sh 

#!/bin/bash

sleep 65

echo "Done."

iMac:~ me$ time ./time_test.sh 

Done.

real 1m5.016s

user 0m0.003s

sys 0m0.006s

An hour, 2 minutes, and 8 seconds (sleep 3728):

real 62m8.083s

user 0m0.003s

sys 0m0.007s

A script that completes in approximately 2 seconds (sleep 2):

real 0m2.014s

user 0m0.003s

sys 0m0.006s

Mystery solved.