update

azurerm/internal/services/automation/resource_arm_automation_schedule.go

@@ -238,11 +238,19 @@ func resourceArmAutomationScheduleCreateUpdate(d *schema.ResourceData, meta inte
 	properties := parameters.ScheduleCreateOrUpdateProperties
 
 	//start time can default to now + 7 (5 could be invalid by the time the API is called)
+	loc, err := time.LoadLocation(timeZone)
+	if err != nil {
+		return fmt.Errorf("error parsing timezone timezone %q: %s", timeZone, err)
+	}
 	if v, ok := d.GetOk("start_time"); ok {
 		t, _ := time.Parse(time.RFC3339, v.(string)) //should be validated by the schema
+		duration := time.Duration(5) * time.Minute
+		if t.Sub(time.Now().In(loc)) < duration {
+			return fmt.Errorf("start_time is %q and should be at least %q in the future", t, duration)
+		}
 		properties.StartTime = &date.Time{Time: t}
 	} else {
-		properties.StartTime = &date.Time{Time: time.Now().Add(time.Duration(7) * time.Minute)}
+		properties.StartTime = &date.Time{Time: time.Now().In(loc).Add(time.Duration(7) * time.Minute)}
 	}
 
 	if v, ok := d.GetOk("expiry_time"); ok {