Timer cycling correctly?

[JMOwens]

Hi all,
I have a timer running my program at 1/60 second, as indicated below:

def masterLoop(num):
.
[main program here]
.
viz.callback(viz.TIMER_EVENT,masterLoop)
viz.starttimer(0,1/60,viz.FOREVER)

However, when I insert a viz.elapsed() into the callback, it returns values of roughly 0.004. I may be misunderstanding the function, but shouldn't it be returning 0.017, which is 1/60? Sorry if this is a dumb question, but it's really important that this timer is cycling correctly. Thanks for your help!