noun: a clock-watching form of procrastination, in which the procrastinator schedules the "start time" of a dreaded task based on the next "half-hour" mark of the clock. For example, if the clock reads "1:35", a procrastinator employing the half-hour clock technique will start the task when the clock strikes "2:00", usually filling in this time gap with activities such as web surfing and masturbation. The technique is popular amongst perfectionists, numerologists, the obsessive compulsive and unemployed spectrum of procrastinators.
Hey, it's 4:47. Did you finish writing that cover letter?
Actually I did not. I was waiting till 5:00 to start. I'm using the half-hour clock technique.