Working function that adds calendar event to calendar (ICS / Calendar / Outlook / Gmail)

gistfile1.txt

def send_appointment(attendee_email, organiser_email, subj, description, location, start_hour, start_minute):
    # Timezone to use for our dates - change as needed
    tz = pytz.timezone("Europe/London")
    start = tz.localize(dt.datetime.combine(datetime.utcnow(), dt.time(start_hour, start_minute, 0)))
    # Build the event itself
    cal = icalendar.Calendar()
    cal.add('prodid', '-//My calendar application//example.com//')
    cal.add('version', '2.0')
    cal.add('method', "REQUEST")
    event = icalendar.Event()
    event.add('attendee', attendee_email)
    event.add('organizer', organiser_email)
    event.add('status', "confirmed")
    event.add('category', "Event")
    event.add('summary', subj)
    event.add('description', description)
    event.add('location', location)
    event.add('dtstart', start)
    event.add('dtend', tz.localize(dt.datetime.combine(datetime.utcnow(), dt.time(start_hour + 1, start_minute, 0))))
    event.add('dtstamp', tz.localize(dt.datetime.combine(datetime.utcnow(), dt.time(6, 0, 0))))
    event['uid'] = uuid.uuid4()  # Generate some unique ID
    event.add('priority', 5)
    event.add('sequence', 1)
    event.add('created', tz.localize(dt.datetime.now()))

    # Add a reminder
    alarm = icalendar.Alarm()
    alarm.add("action", "DISPLAY")
    alarm.add('description', "Reminder")
    event.add_component(alarm)
    cal.add_component(event)

    # Build the email message and attach the event to it
    msg = MIMEMultipart("alternative")

    msg["Subject"] = subj
    msg["From"] = organiser_email
    msg["To"] = attendee_email
    msg["Content-class"] = "urn:content-classes:calendarmessage"

    msg.attach(MIMEText(description))

    filename = "invite.ics"
    part = MIMEBase('text', "calendar", method="REQUEST", name=filename)
    part.set_payload(cal.to_ical())
    encode_base64(part)
    part.add_header('Content-Description', filename)
    part.add_header("Content-class", "urn:content-classes:calendarmessage")
    part.add_header("Filename", filename)
    part.add_header("Path", filename)
    msg.attach(part)

    smtp = smtplib.SMTP('smtp.postmarkapp.com', 587)

    smtp.starttls()
    smtp.login(os.environ['POSTMARK_KEY'], os.environ['POSTMARK_KEY'])
    # Send the email out
    smtp.sendmail(msg["From"], [msg["To"]], msg.as_string())
    smtp.quit()

send_appointment("nathan.ganser@interspark.com", "test@autogmail.com", "Meeting test", "What a day\nGreat.", "https://zoom.com/9989898", 10, 10)