Intent is the application of Desire and Will to creation. When a potter sits down at a wheel to spin a vase, his desire to spin a vase, coupled with the will to get it done, is instrumental in the force used to form the new creation.
When we intend something we take a desired creative outcome and direct it (i.e. will it) to happen with the force of Consciousness.
How long it takes to translate intent into creation depends entirely on the persistence and strength of will (i.e. the harder you will it, the faster it will happen), the nature and complexity of our creative intent, our general creative expertise, and the energetic level at which you are creating at. At lower (i.e. denser) levels of physical Creation where Creation vibrates slower, intent requires additional time and effort. Obviously, more complex creative outcomes require longer periods of intense creative intent and more time (and perhaps assistance) to properly unfold.
Intent may be contrasted with Expectation.
"The beginning of spiritual life is conversion, an attitude of the will turning towards God and renouncing the world."
Zoroaster's mystical experiences were precedent by intent, an "ardent desire" to meet Vohu Manah. 
- Lossky, Vladimir. The Mystical Theology of the Eastern Church. New York: St. Vladimir’s Seminary Press, 2002. p. 199.
- Dhalla, Maneckji Nusservanji. History of Zoroastrianism. New York: Oxford University Press, 1938. p. 33.