Paris Hilton may not spend 45 days in prison after all, reports BBC.
Time off for good behaviour and prison overcrowding could mean that she spends three weeks in jail.
"It's possible it could be 21 days, 23 days," said a Los Angeles County sheriff spokesman.
He added, "our jail is bursting at the seams" and that some female inmates had been released after only serving 10 per cent of their sentence.
Paris should not expect any favours just because she is famous, he revealed, "she will be treated like any other low-level security risk."
Meanwhile TMZ, reports that the number of days she will spend behind bars will be unknown until the heiress reports to County Jail.