days; adding 2 points if the defendant committed the instant offense while under any criminal justice sentence, including probation, parole, supervised release, imprisonment, work release, or escape status; adding 2 points if the defendant committed the instant offense less than two years after release from imprisonment on a sentence of sixty days or more or while in imprisonment or escape status on such a sentence, except that if 2 points are added committing the offense while under a criminal justice sentence, adding only 1 point for this item; and adding 1 point for each prior sentence resulting from a conviction of a crime of violence that did not receive any points because such sentence was counted as a single sentence, up to a total of 3 points for this item. The guidelines require "counting prior adult diversionary dispositions if they involved a judicial determination of guilt or an admission of guilt in open court." This reflects a policy that defendants who previously received the benefit of a rehabilitative sentence and then commit further crimes should not be treated with further leniency. Zones There are four sentencing zones: A, B, C, and D. Zone A consists of sentencing ranges of 0–6 months. Zone B consists of sentencing ranges above Zone A but with a maximum penalty of no more than 15 months. Zone C consists of sentencing ranges above Zone B but whose maximum penalty is 18 months or less. Zone D consists of sentencing ranges above Zone C. A defendant in Zone A is eligible for Federal Probation, and no term of imprisonment is required. Probation is also authorized if the applicable guideline range is in Zone B of the Sentencing Table and the court imposes a condition or combination of conditions requiring intermittent confinement, community confinement, or home detention as provided in , but at least one month of the sentence must be satisfied by imprisonment. A split sentence is authorized for defendants in Zone C. That is, Zone C defendants must serve at least half of their sentence in prison. In 2010, the U.S. Sentencing Commission proposed expanding Zones B and C, in recognition of the fact that many offenders are sentenced to 12 months and 1 day in order to receive the benefit of good time under U.S. federal law. Adjustments Reductions in time to be served A 2- or 3-level offense level decrease is typically granted