Setting deadlines

In an aspirational move, I've written some deadlines into my diary for the next three weeks - beautifully staggered in the hope that I might meet them  - for completing and sending off three short stories to magazines or competitions.  I'm hoping that this will help me to be focused and to achieve what I want to in the next few weeks. Do deadlines work for most writers? I suspect that without them I could float on forever, polishing and tweaking and procrastinating.