The basic computation is used when the factors involved are limited to a sentence, jail time, and date received. Penal Law 70.30 (1) states that the sentence commences when the inmate is received in this Department. Penal Law 70.30 (3) states that the sentence is credited with jail time. Correction Law 601-a states that the jail time must be certified by the New York City Department of Corrections or the County Sheriff. Penal Law 70.30 (4) states that good time may be subtracted from the maximum expiration date. Correction Law 803 (1) states the amount of good time. Penal Law 70.40 (1) states that the inmate is eligible for parole after serving his/her minimum term. During certain circumstances an inmate may be released prior to serving his/her minimum term. These are: shock incarceration, sentences of parole supervision (Willard), merit, medical parole, and early parole to deportation. The inmate is usually seen by the Parole Board two months prior to his/her parole eligibility date. The Board may release him or they may hold him for a reappearance at a later date. If the inmate is not released by the Parole Board, he may eventually be released by conditional release. The inmate is usually seen by the Time Allowance Committee four months prior to his/her conditional release date. The Time Allowance Committee reviews the inmates incarceration behavior and programming to decide if he has earned his/her good time. There is no conditional release on a maximum term of life. If he is not released by the parole board or the time allowance committee, he will remain in custody until his/her maximum expiration date.