My callbacks take .6 seconds and happen every 60 seconds -- little chance of overlap. Actually I had put in debugging diags to find this out... I used lhoward's solution below for now and I'll look at Event again in a little while. I have other uses for Event, so I want to get to know it better. The reason I did not use sleep subtracting the function time in the first place is that I was unaware of Time::HiRes.

Thanks for the help and for telling me about Event and Time::HiRes.