In python, use:

	import time
	t1 = time.clock()
	# Do things here...
	t2 = time.clock()
	print t2 - t1

C/C++ under Windows:

	#include <windows.h>	// For high-resolution timer functions.

	LARGE_INTEGER frequency, begin_count,end_count;
	BOOL result;
	double time_elapsed;

	result = QueryPerformanceFrequency(&frequency);
	assert(result);
	result = QueryPerformanceCounter(&begin_count);
	assert(result);
	// Do things here...
	result = QueryPerformanceCounter(&end_count);
	assert(result);
	time_elapsed =
	  ((double)(end_count.QuadPart - begin_count.QuadPart)) / frequency.QuadPart;

C/C++ under Linux:

	#include <time.h>

	clock_t t1, t2;
	t1 = clock();
	// Do things here...
	t2 = clock();
	printf("It took %f seconds.\n", ((double)(t2 - t1))/CLOCKS_PER_SEC);

Java: we only get millisecond resolution(?)

	long t1 = System.currentTimeMillis();
	// Do things here...
	long t2 = System.currentTimeMillis();
	System.out.println(t2 - t1);

Perl:

	use Benchmark;

	$t0 = new Benchmark;
	# ... your CODE here ...
	$t1 = new Benchmark;
	$td = timediff($t1, $t0);
	print "the code took: ", timestr($td), "\n";