HTC One M8 for Windows - Manual (Page 141)

Sending an invitation
You can use Calendar to schedule a meeting or an appointment and invite
people to attend it. An invitation email will be sent to them from the
account that you choose.
You can only invite contacts that are stored or synced on your
phone.
1. In Calendar, create a new appointment.
2. Add details, such as date and time, location, and more.
3. Tap more details.
4. Tap the Calendar field, and then choose the account to use for
sending the invitation.
5. Tap add someone.
6. Invite required and optional attendees by tapping add someone
below each field.
7. When you're done, tap > .
Productivity 141