The likelihood of jail time for a first DUI offense will depend on the specific circumstances of the case and the laws of the state where the offense occurred. In general, first-time offenders do not go to jail but in some instances may face anywhere from one day to six months in jail, with the possibility of probation or alternative sentencing options. Factors such as high blood alcohol concentration (BAC), involvement in an accident, and prior criminal history may also impact the likelihood of jail time. It is important to consult with a legal professional for an accurate assessment of the potential consequences for a first-time DUI offense.