CHAPMAN, Justice.

On September 29, 1945, J.W. Lukers was convicted in the Court of Record of Escambia County, Florida, of the crime grand larceny and sentenced to serve a period of four years at hard labor in Florida State Prison. Lukers perfected an appeal from the judgment of conviction to the Supreme Court of Florida and did not actually begin the service of his four year term of imprisonment at the Florida State Prison until August 10, 1946, where he continued to remain in custody and serve his sentence until the 6th day of January, 1948, when the Florida Parole Commission released him from custody, conditioned on good behavior.

The record discloses that Lukers was taken into custody on the charge or charges that he had violated some of the conditions or provisions of his parole, and a hearing was given him by the Parole Commission on the question of whether or not he had violated the conditions or provisions of the parole under which he was released from prison. As a result of the hearing the conclusion was reached that Lukers had violated the terms and conditions of his parole: (1) by the excessive use of intoxicants on August 12, 1949; (2) on August 14, 1949, by becoming intoxicated and assaulting his wife; and (3) by giving worthless checks on May 17, 1950, and, accordingly, on June 9, 1950, an order was entered by the Parole Commission revoking the parole previously issued and Lukers was returned to the State Prison to serve the unexpired portion of his four year sentence.

Lukers filed in the Circuit Court of Union County, Florida, his petition for a writ of habeas corpus and represented that he was unlawfully restrained and deprived of his liberties by the Honorable Nathan Mayo, as Custodian of Convicts of the State of Florida. It was further contended that the Florida Parole Commission was without legal authority to enter its order dated June 9, 1950, which revoked petitioner's parole, cause his rearrest and thereafter return him to the State Prison to serve the unexpired time of his four year sentence.

The writ issued as prayed for, a hearing was had, and the lower Court held that Lukers was entitled to credit on his four year sentence for the period of time he was at large on parole before his parole was revoked; also the time Lukers served in the State Prison, plus the time he was out on parole, was legally sufficient to fully complete the service of the four year sentence imposed by the Court of Record of Escambia County, Florida. An order was entered permitting an appeal by the State of Florida from the order of discharge to the Supreme Court of Florida. The petitioner began the service of his four year sentence on August 10, 1946, and the order of discharge is dated May 2, 1951. The petitioner served from August 10, 1946, continuously until January 6, 1948, and from June 9, 1950, until May 2, 1951, approximately 27 months and 20 days of a 48 months sentence.

It was the trial Court's view and conclusion that the petitioner was entitled to gain time credits viz.: (1) on the period of time from August 10, 1946, until released on parole on January 6, 1948; (2) during the period the petitioner was at large on parole from January 6, 1948, until the date of the revocation order entered by the Parole Commission on June 9, 1950; and (3) the aggregate of the gain time credits supra, coupled with the time actually served in the State Prison, were sufficient to discharge the four year prison term imposed by the Court of Record of Escambia County.

Section 954.06, F.S.A., prescribes the method or rule for computation of gained time for good conduct on the part of prisoners by the Board of Commissioners of State Institutions. Pertinent thereof is the following provision: "For each sustained charge of escape or attempted escape, mutinous conduct or other serious misconduct, all the commutations which shall have accrued in favor of the prisoner up to that day shall be forfeited, except that in case of escape if the prisoner voluntarily returns without expense to the state, then such forfeiture may be set aside by the board of commissioners of state institutions if in their judgment his subsequent conduct entitles him thereto." (Emphasis supplied.) It will be observed that a prisoner may forfeit by misconduct gain time accumulated by him for good behavior. The Board of Commissioners may restore the gain time to the person if his subsequent conduct entitles him to it. The petitioner may have the forfeited time restored in the final computation of the time served on his sentence. The gain time allowance provided for by this statute may be forfeited by misconduct on the part of the prisoner during the life of the sentence. The cases generally hold that the granting of the gain time allowance is an act of grace rather than a vested right which may be withdrawn, modified, or denied, dependent on the course of conduct of the prisoner. The ends to be obtained are the reform and rehabilitation of the prisoner and his return to and discharge of his duties to society. 41 Am.Juris. 919.

Section 32 of Article 16, being an amendment to the Constitution of Florida, F.S.A., was approved by the voters of Florida at the General Election of 1940. This amendment authorized the Legislature to implement the amendment by a statutory enactment which later became Chapter 20519, Acts of 1941, Laws of Florida. Chapter 947, F.S.A., Section 947.13, F.S.A., grants powers and duties to the Parole Commission: the Commission shall have the power to determine what persons shall be placed on parole; and the parole shall be in writing. Section 947.21 provides that a violation of a parole may render the parolee liable to arrest and return to prison to serve out the term for which he was sentenced. No part of the time he may have been on parole shall in such event in any manner diminish the time of such sentence.

It was not the intention of the Legislature by the enactment of Section 947.21 to confer on the Parole Commission the power or authority to suspend, modify or set aside the judgment of a court lawfully imposed in criminal cases, but provided that the period of time the prisoner was on parole and not actually serving the sentence would in no manner decrease nor diminish the time imposed by the original court sentence. In other words, the time of imprisonment provided for in the judgment would simply be tolled during the parole period. If the parole was violated and the parolee returned to prison by an order of the Commission, then the time of sentence would be computed from the date of the parole order without gain time allowance during the parole period. This construction is in line with the weight of authority from other jurisdictions having similar statutes. 67 C.J.S., Pardons, § 23, p. 621.

The order of discharge entered below is reversed with directions to remand the petitioner to the custody of the appellant as Custodian of the Florida State Prison.

SEBRING, C.J., and ADAMS and ROBERTS, JJ., concur.