When you want to know how long does it take to run a process, just use time command as a prefix
$ time my_program arg1 arg2
real 0m0.003s
user 0m0.000s
sys 0m0.004s- real : wall clock time, mean time to start to finish your process
- user : CPUs-time outside the kernel
- sys : CPUs-time within the kernel
real+sys result is total multi CPUs time (so if you have a multi core CPUs, it is often bigger than real)