Higher Ordinations: any time throughout they year
Ordination preparation period: depending on the readiness of the applicant, as well as the approval of the teacher and resident Saṅgha
During the ordination preparation period, a special Vinaya course provides applicants for ordination an overview of the monks’ rules, so that there are no surprises after ordination. Applicants also learn to sew their own robes, make brooms, and familiarize themselves with Pāli pronunciation.
Initially a person becomes a postulant, a period that gives him the opportunity to voluntarily practice as if one were a monk already, but without the formal Vinaya rules. This initial period can last anything between 3, 6, or 12+ months; individual differences are recognized, which may lead to a shorter or longer path towards higher ordination.
“A householder or householder’s son or one born in some other clan hears this Dhamma. He then acquires faith in the Tathāgata and considers thus: ‘Household life is crowded and dusty; life gone forth is wide open. It is not easy, while living at home, to lead the spiritual life that is utterly perfect and pure as a polished conch shell. Suppose I shave off my hair and beard, put on ochre robes, and go forth from the household life into homelessness.’ On a later occasion, having abandoned a small or a large fortune, having abandoned a small or a large circle of relatives, he shaves off his hair and beard, puts on ochre robes, and goes forth from the household life into homelessness.” (AN 4.198)