I am interested in your question because I am doing some research on spirituality in my website spi.st and time is an essential part in the process of growing, self improvement, following a path.
I think that setting deadlines is essentially positive, because it makes your plans real, avoids forgetting, helps to be serious, fair, solid.
However, there are risks as well, depending on the kind of growth you want cultivate.
Deadlines contain the risk of distracting you from listening to your personality, your humanity, the specific rhythms, pace, speed of your body, your mind, your psychology, you.
For example, if you want to grow in your ability to love people, you can set deadlines, but you might loose sight of your creativity in this process: creativity can mean that your personality needs to set its own spontaneous pace and speed to develop its new and maybe even revolutionary ideas: you can consider how contradictory the following statements are: "I want to make a discovery within the next two months", "I want to create a revolutionary idea within this year": you can see how the idea of a deadline is kind of contradictory and even funny if connected to creativity.
Another problem about deadlines is frustration: it depends how you react if you fail in respecting a deadline: if you end up thinking that you are a failure, you are not good, this means that you lost sight of the importance of listening to yourself.
On the contrary, it can also happen that being successful in reaching a goal within a certain time can make you blind about the amount of work, of improvement and refinement that you still need to do: for example, you might set the deadline of learning and understanding the philosophy of Heidegger, or of Nietzsche, within the next two months. After reaching the deadline, you might think that you have been fully successful, loosing sight of the fact that most philosophies are so deep, so rich, so open to unknown consequences, that most probably we will never finish understanding them.

A martial arts student went to his teacher and said earnestly, "I am devoted to studying your martial system. How long will it take me to master it." The teacher's reply was casual, "Ten years." Impatiently, the student answered, "But I want to master it faster than that. I will work very hard. I will practice everyday, ten or more hours a day if I have to. How long will it take then?" The teacher thought for a moment, "20 years."

http://users.rider.edu/~suler/zenstory/workhard.html

My goal is to grow old and die, and to do it as slowly as possible. A man focussed on goals and always in a hurry is called a "bisy backson". The trouble with being goal oriented and busy is that one misses the wonderful scenery and the wonderful characters of the world. It's just not much fun, and what is life for if it's not much fun?

Hear, here,

So time limits for goals, as part of the very goals themselves can be set by the individual who wants to achieve said goals, at least I often set time limits for myself in which to achieve certain goals, anybody else? — HardWorker

I don't set goals.

My goal is to grow old and die, and to do it as slowly as possible — unenlightened

:lol: Not in the least sense interested in the live fast, die young crowd, eh?

Look at how Mayflies live (life expectancy 5 mins for females - 2 days for males)! These insects accomplish everything some lucky humans do (birth, childhood, adulthood, family, death and all the intervening crap), it's just that everything is faster, a lot faster, for them. Talk about living in the fast lane!

I know some people who have no patience when watching movies. The parts they get thems stoked are played at normal speed and the parts that are boring are fast forwarded. I wish we could do that in the real word. Skip to the interesting part storyteller, forget the buildup, I want to know how it ends!

A man focussed on goals and always in a hurry — unenlightened

Goals! I recall a video clip in which Daniel Bonevac (philosopher) claims that a goal-oriented mindset may not be the best way to live life. Did he mention stress? memory read failure.

I don't set goals. — Tom Storm

You let other people set goals for you?

Skip to the interesting part storyteller, forget the buildup, I want to know how it ends! — Agent Smith

It ends in aging, illness, and death. How else?

So time limits for goals, as part of the very goals themselves can be set by the individual who wants to achieve said goals, at least I often set time limits for myself in which to achieve certain goals, anybody else? — HardWorker

It's standard to do so. The term is "smart goals".

It ends in aging, illness, and death. How else? — baker

Yup. I was thinking more in terms of exhilarating stuff that happen before we kick the bucket.

Thanks for SMART, smarty pants.

I was thinking more in terms of exhilarating stuff that happen before we kick the bucket. — Agent Smith

You mean, the distractions?

You mean, the distractions? — baker

Not all stories end in physical death. Exciting stuff happen before we cross the river Styx.

Exciting how?

Exciting how? — baker

Read a book baker, preferrably one that doesn't end with the deaths of all the characters.

I really like that chart, thanks.