First things first: looking for a new job on the company's time is a bad idea. But sometimes, life intervenes -- for instance, if you work 14 hours a day, and most weekends, it can be hard to carve out time that's really "yours." So what do you do to minimize the risk of getting caught?
The best time to look for a job is when you have a job, but that doesn't make the process any less fraught. For one thing, there are only so many personal days you can take and so many "dentist appointments" you can schedule before the jig is up. So what time is the right time to let your manager know that you're thinking of moving on?