|Deadlines are a very important principle for success. Without deadlines, your work might not ever get finished. Deadlines are included in my MEAT method and FTAD methods.
Using an egg-timer is another way to set a deadline. If you're having trouble finishing anything, just set a deadline. The more real the deadline the better. If your failing at something see if you have a deadline. You probably don't.
I got this book published on Amazon by setting a deadline and sticking to it. Publicly stating your deadline can also help you meet it. If you have people that work for you or are suppliers of yours, always have them set deadlines. Even better to commit publicly in a meeting to the deadline.
This method is also part of Parkinson's law which states "Work expands to the time allotted." Set hourly, daily, monthly, quarterly or yearly deadlines to help you achieve success.
What to do if someone asks you the magic question, "When can I expect it?" Unless you know for sure, a general rule of thumb is to double your estimate. I also advise you to include, "... if nothing unexpected comes up." This way you're covered if your computer system crashes or you lose power or some other unexpected event occurs.