The Judge signs the order establishing the time to serve on an offense. The Department of Corrections (DOC) presently operates 22 probation detention centers throughout Georgia. Refer to link below for more detail. Depending on the nature of the offense and the judgment & sentence order, probation detention centers are designed to provide short-term confinement of probationers sentenced by the courts, normally for a period of 90 to 180 days. This answer is for informational purposes as I do not practice law in the state of GA. Contact a GA attorney for legal advice. You can find an attorney through Avvo.com and check out the GA Bar Association. See link below.
The amount of time an adult probationer will spend in a probation detention center is set either by a Judge or plea agreement between the criminal defendant and the State.
In the case of an agreement between the State and the Defendant - the Judge must approve and accept the agreement before sentencing. If there is no agreement, the Judge will hear from probation, defense counsel and the prosecution for any reccomendations as to sentence. He will consider each probationer on a case by case basis and then pronounce sentence.
Any PDC sentence must be indeterminate (meaning it has a range of months to serve). For example, a common PDC sentence is 300-365 days; whereas a probationer who has no violations at the detention facility (such as fighting, etc...) will be released after 300 days. Should that probationer accrue violations at the facility - that could delay his release until he has served 365 days. The shortest PDC sentence I have seen is 90-120 days or approximately 3-6 months. However, it is not uncommon that an inmate will be given credit for the time he has already served in the County Jail prior to sentencing. With credit for time served - any sentence may be considerably shorter.
Here are some hypothetical examples:
A man is sentenced to 10-12 months in a probation detention center. If he has no rule violations at the PDC - he can be released after serving 10 months. To the contrary, as he accrues violations - he may serve the entire 12 months. Assume that the Judge gave the man "Credit for Time Served". If the man was incarcerated in the county jail for 8 months prior to being sent to the PDC - he would only have to serve between 2 and 4 months at the PDC.
A man is sentenced to 10-12 months in a probation detention center. If he has no rule violations at the PDC - he can be released after serving 10 months. To the contrary, as he accrues violations - he may serve the entire 12 months. Assume that the Judge gave the man "Credit for Time Served" from "This day Forward". If the man was incarcerated in the county jail for 8 months prior to being sent to the PDC - he would still look forward to 10-12 months more at a PDC. However - should the man sit in a county jail for weeks or months while waiting on bed space at the PDC, than his PDC sentence would be reduced by the amount of time between the day he was sentenced and the date he was transferred from jail to the PDC.
All sentences, in the end, are in the sole discretion of the Trial Judge; since he must either decide the sentence himself or accept a negotiated sentence between the State and the Defendant.