Approx. 3-4 times per year, the regular service is shifted either to Sat. evening, or Sun. afternoon. Most often--once in March, once in August, shifted to Saturday; Sunday before Thanksgiving, shifted to Sunday afternoon. Please e-mail to be sure.
In addition to 1st, 3rd, 5th Sundays, the Lord's Supper is also offered on festivals that happen to fall on the 2nd or 4th Sundays--specifically, Easter, Pentecost, Reformation.