etime

Purpose

Elapsed time.

e = etime(t2,t1)

etime(t2,t1) returns the time in seconds between clock output vectors t1 and t2.

Calculate how long a 2048-point real FFT takes.

x = rand(2048,1);
t = clock; fft(x); etime(clock,t)
          
ans =
    0.4167

etime fails across month and year boundaries. It can be fixed with some effort; see the etime M-file.