When jurors are excused, it means only that there are proper and lawful reasons for the excusals. The first day of service is normally limited to jury selection for trials held during the following week. Jurors selected to serve cases will be asked to return and serve on the dates of that trial. Most trials last one day. The dress code of the court is general business attire.
Casual attire is acceptable.
However, you may not wear tank tops, shorts, or flip-flops. Be on time for court. The trial cannot proceed until all jurors are present. Sit in the same seat in the jury box. This allows the clerk, judge, and lawyers to identify you more easily.