Print execution time of a shell command

Question

Is is possible to print the execution time of a shell command with following combination?

root@hostname:~# "command to execute" && echo "execution time"

Answer 1

Adding to @mob's answer:

Appending %N to date +%s gives us nanosecond accuracy:

start=`date +%s%N`;<command>;end=`date +%s%N`;echo `expr $end - $start`

Answer 2

In zsh you can use

=time ...

In bash or zsh you can use

command time ...

These (by different mechanisms) force an external command to be used.