i keep deadlines by being realistic about how long a job will take when i first make the deadline.

i figure out honestly how long each part of the job will take, how many hours i can devote to the total job each day, and then i add 15% onto the time for things going wrong.

most people i know just throw a random amount of time on their deadlines, and feel bad when they either can't meet them or have to push themselves insanely. when i've asked them, they say they came up with their deadline "because it seemed like a reasonable amount of time". obviously it wasn't, or they wouldn't be struggling.

if you are a motivated self-starter, do you need a deadline? i always work a lot, but for some projects, i DO put a deadline on it. i'm not even sure why i do that, as i never stop working on something till it's finished.