Let me tell you a story about a coworker (from another place) named Donita. She wasn't paying much attention to her spedometer while on the interstate and got nailed for 92 in a 65. She had a clean driving record, no other tickets. Reckless driving requires actually going to court, and prior to her court date she got her spedometer calibrated and she took a driver's ed course, the same course the courts often order. We worked with real estate, she knew how to dress properly, so likely a proper presentation in court. Her schedule that day was 11am, court was 9am, she figured she'd have time for court before work.
When the judge found her guilty, he decided that the high speed she was going was worth jail. She was immediately taken into custody, and it was either late that evening or the next day that she was finally released. Meanwhile, we at work were trying to figure out why Donita was a NCNS, as that was not like her at all. She also had weekend jail for either a month or 6 weeks, I don't remember which.
While the office gossip was going around once we knew what happened to her, another coworker named Rebecca said she also had been sentenced to jail over speeding. She had not been so high over the speed limit that she got reckless driving, but she had 5 over a short period of time. Ticket number five got her a week in jail.
So even with a conviction, 2 days in jail could be over something absolutely minor.