Creativity comes out in many ways. Some people are photographers, some are writers, while others paint or draw. It's a way to express feelings and oftentimes is the source of happiness for people.
However, when you place deadlines or try to force it, it's often no good.
You know when you're in school and you have a paper due and you remember last minute so you sit down and force yourself to simply finish it? You probably turn in a paper that is simply a Redbull and sleep deprived rant. You'll skate by with a C+ and call it day. Even the most creative people sometimes do this.
The creative process is different for everyone, and trying to force that process to happen can be dangerous for creative people.
It removes the fun of being creative for most people. Taking your means of self-expression and relaxation and forcing it to happen on a timeline makes it work; work that nobody wants to do.
Most creative individuals won't put in as much effort if they are told to make work by a certain date.
For example, a friend of mine who is a sketch artist is always asked to sketch things by family and friends and their work is often done last minute. Making it not the best of their work.
If you want the best work of a creative individual, allow them to create on their own terms. Sometimes their creative process takes days or even weeks and that is probably the work of theirs that you see and enjoy.
When I'm asked to write for people, I usually scribble thoughts down and it's mediocre. When I want to surprise someone with writing, I take weeks to carefully write out my work and it's something I'm really proud of.
Creative people are most proud of the work they do that is not forced.