Subscribe (iCal link)
If you use Apple Calendar, Microsoft Outlook, or other iCal-compatible desktop calendar application, you can subscribe to the DNHS calendar. Updates to the DNHS calendar will automatically sync with your desktop calendar. Instructions from Apple to subscribe to a Calendar on your iPhone are here.
Subscribe (Google link)
If you use Google Calendar, you may use this link to automatically import the DNHS calendar into your Google calendar to subscribe.