I work rotating shifts but I generally plan to leave an hour before my shift starts. That's about 30 minutes of riding, 10 minutes to change clothes and walk to the shop, and 20 minutes spare.

In reality, I'm more of a procrastinator than I claim to want to be, and often rush out of the garage at the last possible second, pedal like hell, and barely make it in time. I don't enjoy doing it, so you'd think I'd learn. But I don't. I do it again, and again, and again...