:According to the Rhode Island Superior Court website:
The Superior Court has implemented a one day - one trial system in Washington and Newport counties to make more efficient use of jurors' time. This system of requiring petit jurors to serve for either one day or for the duration of one trial permits those not selected to serve on a case to be dismissed at the end of their first day. Similarly, a two day - one trial system has recently been established for Providence/Bristol and Kent Counties. This program is a cost saving measure, and is also beneficial to employers, as employees are able to fulfill their civic obligation with a minimal amount of time away from work.Source
Cook County, Illinois also has a one-day/one-trial system. You show up to the courthouse: if you're picked for a jury, you serve on that jury and then you're finished. If you're not chosen that day, then you have fulfilled your jury service and can't be called again for another six months. It's a much better system than many counties which require jurors to serve for longer periods and, in effect, keep them "on call" for the entire time.
On the other hand, (and you need to be aware of this), the one-day/one-trial system runs through a lot
of jurors very quickly, so judges are very reluctant to allow anyone
to get out of jury duty and much more inclined to punish those who shirk their duty.
My advice (along with practically everyone else here): when you get the notice, show up. If you're chosen, serve.