add comparison helpers

clocktime.go

@@ -54,6 +54,38 @@ func (t ClockTime) Time() time.Time {
 	return time.Date(1970, 1, 1, t.Hour, t.Minute, t.Second, 0, time.UTC)
 }
 
+// IsZero checks if the ClockTime is zero (00:00:00) or nil.
+func (t *ClockTime) IsZero() bool {
+	return t == nil || (t.Hour == 0 && t.Minute == 0 && t.Second == 0)
+}
+
+// Equal checks if two ClockTime instances are equal.
+func (t ClockTime) Equal(other ClockTime) bool {
+	return t.Hour == other.Hour && t.Minute == other.Minute && t.Second == other.Second
+}
+
+// Before checks if the ClockTime is before another ClockTime.
+func (t ClockTime) Before(other ClockTime) bool {
+	if t.Hour != other.Hour {
+		return t.Hour < other.Hour
+	}
+	if t.Minute != other.Minute {
+		return t.Minute < other.Minute
+	}
+	return t.Second < other.Second
+}
+
+// After checks if the ClockTime is after another ClockTime.
+func (t ClockTime) After(other ClockTime) bool {
+	if t.Hour != other.Hour {
+		return t.Hour > other.Hour
+	}
+	if t.Minute != other.Minute {
+		return t.Minute > other.Minute
+	}
+	return t.Second > other.Second
+}
+
 // MarshalJSON implements the json.Marshaler interface for ClockTime.
 func (t ClockTime) MarshalJSON() ([]byte, error) {
 	return json.Marshal(t.String())