launchd overlapping jobs

[spookybathtub]

I'm new to launchd, but I hear it's the new cron, so I need to setup a repeating job. I need to run a script once per hour, exactly on the hour. This script takes about 1 hour and 55 seconds to run, and this piles up, so launchd is getting backlogged. What I mean is, after 10 hours, my script is being run almost 10 minutes too late. How can I make it start the next job before the old one is completed to fix this?