diff --git a/calendar.go b/calendar.go
index 684d51b..5120ecb 100644
--- a/calendar.go
+++ b/calendar.go
@@ -95,7 +95,10 @@ func updateDay(calId string, date time.Time, classes []Class) error {
 			continue
 		}
 
-		ev := class.buildEvent(date)
+		ev, err := class.buildEvent(date)
+		if err != nil {
+			return err
+		}
 
 		old := eventMap[ev.Summary]
 
diff --git a/class.go b/class.go
index 434256b..05b4fae 100644
--- a/class.go
+++ b/class.go
@@ -40,7 +40,7 @@ func (c Class) tagsMatch(t time.Time) bool {
 	return true
 }
 
-func (c Class) buildEvent(t time.Time) *calendar.Event {
+func (c Class) buildEvent(t time.Time) (*calendar.Event, error) {
 	dateStr := t.Format("2006-01-02")
 
 	ev := &calendar.Event{
@@ -56,12 +56,11 @@ func (c Class) buildEvent(t time.Time) *calendar.Event {
 		Attendees: []*calendar.EventAttendee{},
 	}
 
-	attendees := c.Students
-	if len(attendees) == 0 {
-		attendees = allStudents
+	if len(c.Students) == 0 {
+		return nil, fmt.Errorf("class with no students: %s", c.Summary)
 	}
 
-	for _, student := range attendees {
+	for _, student := range c.Students {
 		ev.Attendees = append(
 			ev.Attendees,
 			&calendar.EventAttendee{
@@ -74,5 +73,5 @@ func (c Class) buildEvent(t time.Time) *calendar.Event {
 		ev.Description = fmt.Sprintf(`Zoom: %s`, c.Zoom)
 	}
 
-	return ev
+	return ev, nil
 }
diff --git a/classes-hummingbirds.go b/classes-hummingbirds.go
index 03547f3..ed68ba4 100644
--- a/classes-hummingbirds.go
+++ b/classes-hummingbirds.go
@@ -4,12 +4,12 @@ import (
 	"time"
 )
 
-var allStudents = []string{
+var allHummingbirds = []string{
 	"adabelle.pratt@heliosns.org",
 	"oliver.park@heliosns.org",
 }
 
-var greenStudents = []string{
+var greenHummingbirds = []string{
 	"adabelle.pratt@heliosns.org",
 	"oliver.park@heliosns.org",
 }
@@ -21,6 +21,7 @@ var classesHummingbirds = []Class{
 		End: "09:00",
 		Days: weekDaysButFriday,
 		Zoom: "https://us02web.zoom.us/j/2274643506?pwd=Nm5NUXMwOVJKbEUzNE5VSkZCQzJ2UT09",
+		Students: allHummingbirds,
 	},
 	Class{
 		Summary: "🏫 Community Meeting",
@@ -28,6 +29,7 @@ var classesHummingbirds = []Class{
 		End: "09:00",
 		Days: []time.Weekday{Friday},
 		Zoom: "https://zoom.us/j/96371462107",
+		Students: allHummingbirds,
 	},
 	Class{
 		Summary: "🔢 Math (Claudia & Rachel)",
@@ -45,6 +47,7 @@ var classesHummingbirds = []Class{
 		Start: "09:40",
 		End: "10:00",
 		Days: weekDays,
+		Students: allHummingbirds,
 	},
 	Class{
 		Summary: "🐛 Theme",
@@ -52,6 +55,7 @@ var classesHummingbirds = []Class{
 		End: "11:30",
 		Days: weekDaysButFriday,
 		Zoom: "https://us02web.zoom.us/j/2274643506?pwd=Nm5NUXMwOVJKbEUzNE5VSkZCQzJ2UT09",
+		Students: allHummingbirds,
 	},
 	Class{
 		Summary: "❤️ SEL",
@@ -59,6 +63,7 @@ var classesHummingbirds = []Class{
 		End: "11:15",
 		Days: []time.Weekday{Friday},
 		Zoom: "https://us02web.zoom.us/j/2274643506?pwd=Nm5NUXMwOVJKbEUzNE5VSkZCQzJ2UT09",
+		Students: allHummingbirds,
 	},
 	Class{
 		Summary: "📖 Literacy (Green)",
@@ -66,7 +71,7 @@ var classesHummingbirds = []Class{
 		End: "12:00",
 		Days: []time.Weekday{Monday, Wednesday},
 		Zoom: "https://us02web.zoom.us/j/2274643506?pwd=Nm5NUXMwOVJKbEUzNE5VSkZCQzJ2UT09",
-		Students: greenStudents,
+		Students: greenHummingbirds,
 	},
 	Class{
 		Summary: "🤸 PE (Yellow/Green)",
@@ -74,7 +79,7 @@ var classesHummingbirds = []Class{
 		End: "12:00",
 		Days: []time.Weekday{Tuesday},
 		Zoom: "https://zoom.us/j/97472507748?pwd=cW5vUFhyUjNTS2toWlZGN254U1ZqZz09",
-		Students: greenStudents,
+		Students: greenHummingbirds,
 	},
 	Class{
 		Summary: "💡 iLab (Yellow/Green)",
@@ -82,7 +87,7 @@ var classesHummingbirds = []Class{
 		End: "12:00",
 		Days: []time.Weekday{Thursday},
 		Zoom: "https://us02web.zoom.us/j/86403635026?pwd=S2t1WkN2dnNJZlFkejdEbjRsUmNNUT09",
-		Students: greenStudents,
+		Students: greenHummingbirds,
 	},
 	Class{
 		Summary: "📚 Library",
@@ -90,6 +95,7 @@ var classesHummingbirds = []Class{
 		End: "12:00",
 		Days: []time.Weekday{Friday},
 		Zoom: "https://us02web.zoom.us/my/helioslibrary?pwd=cWd4RjNqNXZXNjRjM2dYQVhYeS9Xdz09",
+		Students: allHummingbirds,
 	},
 	Class{
 		Summary: "🇲🇽 Spanish",
@@ -117,7 +123,7 @@ var classesHummingbirds = []Class{
 		End: "13:30",
 		Days: []time.Weekday{Friday},
 		Zoom: "https://zoom.us/j/96449009866?pwd=dlBHYUwxaDRReFhjVmRKZ0Vhdjdkdz09",
-		Students: greenStudents,
+		Students: greenHummingbirds,
 	},
 	Class{
 		Summary: "🎨 Art (Blue/Green)",
@@ -125,7 +131,7 @@ var classesHummingbirds = []Class{
 		End: "14:45",
 		Days: []time.Weekday{Friday},
 		Zoom: "https://us02web.zoom.us/j/85434303018?pwd=c3EzQVNCMmk0L0o4bVF4QW85RTZHZz09",
-		Students: greenStudents,
+		Students: greenHummingbirds,
 	},
 	Class{
 		Summary: "👋 Closing Circle",
@@ -133,6 +139,7 @@ var classesHummingbirds = []Class{
 		End: "15:15",
 		Days: []time.Weekday{Friday},
 		Zoom: "https://us02web.zoom.us/j/2274643506?pwd=Nm5NUXMwOVJKbEUzNE5VSkZCQzJ2UT09",
+		Students: allHummingbirds,
 	},
 	Class{
 		Summary: "🍎 Rachel & Oliver",