Office 365 Calendar via EWS connection FAQs

OnceHub communicates with your Office 365 Calendar using the Exchange Web Services (EWS) API, a well-established official Microsoft protocol. All credentials and data traffic are fully encrypted.

In this article, you'll find answers to some of the most common questions related to your Office 365 Calendar via EWS connection

Connecting to your Office 365 Calendar via EWS

  1. Sign in to your OnceHub Account.
  2. Open the left sidebar, click on Profile and select Calendar connection. If you are switching connections, you must disconnect from your previous connection first.
  3. Click the Connect button next to Office 365 Calendar via EWS.
  4. The Connect to Office 365 via EWS pop-up will open. Enter your credentials and click Connect.

Learn more about connecting to Office 365 Calendar via EWS

Even if your credentials are correct, the connection might not be successful due to various Office 365 configurations. In that case, you may need to provide additional information. Learn more about troubleshooting Office 365 via EWS connection issues

Most common questions

Which Office 365 edition is required to connect with OnceHub? 

To be able to connect OnceHub to your Office 365 Calendar, you must have a calendar in Outlook on the web for business (Outlook Web App), which is provided with Exchange Online. Learn more about which Office 365 edition is required

How does OnceHub connect with Office 365 Calendar via EWS?

OnceHub communicates with your Office 365 Calendar using the Exchange Web Services (EWS) API, a well-established official Microsoft protocol. All credentials and data traffic are fully encrypted. The integration uses the permissions Users already have when viewing calendars (for example: only free/busy), so no new information will be accessible to them.

How are my credentials stored?

When you enter your credentials to connect OnceHub to your Office 365 Calendar, your password is encrypted with AES-256 (Advanced Encryption Standard) and stored in our cloud database.

Learn more about how sign-in credentials are stored and protected by OnceHub

What is busy time caching?

Some Office 365 servers have a relatively slow response time, and some apply a throttling policy, intended to moderate data traffic. To ensure fast performance, we employ a caching mechanism for the busy times in your connected Office 365 Calendar.

Can OnceHub connect with shared Office 365 Calendars or resources (rooms)?

Your default calendar, sub-calendars (folders) and calendars that have been shared with you are supported. 

Rooms are supported in InviteOnce. Learn more about adding rooms in InviteOnce

Resource calendars are not supported yet for ScheduleOnce.

What happens if my password changes?

If you connected using your own Office 365 password, and the password is changed, you must reconnect with the new password to restore the connection. Learn more about resolving connection issues

Can I set default Office 365 Calendar reminders when events are created via OnceHub?

Yes, you can configure default Office 365 Calendar reminders in the connected Office 365 Calendar. 

Go to your OnceHub Account and click Profile in the left sidebar. Click on Calendar connection and use the Default Office 365 Calendar reminders drop-down menu to select the value that you want.

Figure 1: Default Office 365 Calendar reminders

Learn more about configuring your Office 365 Calendar via EWS connection

Can I disable the Office 365 Calendar invite that is sent to my Customers? 

In ScheduleOnce, you can disable the Office 365 Calendar invite email by going to Setup -> relevant Booking page -> Customer notifications and unchecking the box that sends the Office 365 Calendar invite email. 

Note The Customer notifications section will be on the Event type if the Booking page is associated with at least one Event type.

In InviteOnce, you can disable the Office 365 Calendar invite email in Step 3 of the invite to self-schedule or schedule on behalf processes.

I cannot see my scheduled meeting in Office 365 Calendar

In your Office 365 Calendar, make sure that the calendar in which your meeting was scheduled is selected. Find it in the calendar list in the left bar and click it to select it. 

You can also select the activity in the ScheduleOnce Activity stream, then click the action menu (three dots) in the right-hand pane and select View Calendar event (Figure 2).

Figure 2: View Calendar event

Why do my busy times appear in wrong time slots?

This might be due to time zone differences between the account time zone in your Office 365 account and the time zone on your Booking page. To change the time zone:

  • In ScheduleOnce: Go to the Overview section of your Booking page and edit the page's time zone.
  • In InviteOnce: Make sure you have selected the correct timezone in Step 2 of invite to schedule and schedule on behalf
  • In Office 365: Click on Settings -> Options - > Settings -> Regional and change the time zone.
    Reload/refresh the ScheduleOnce or InviteOnce page to reflect the change.

Learn more about busy time in Office 365 Calendar

I’m already connected with one Office 365 account. How do I switch to another?

Your account can only be connected to one calendar at a time. If you want to switch from one Office 365 Calendar to another, you will need to disconnect the previous one and then connect the new one.

Disconnect your calendar by going to your OnceHub Account, opening the left sidebar, and selecting Profile -> Calendar connection. Disconnect your Office 365 account and reconnect with the new Office 365 account.

NoteYou can switch your calendar connection accounts without having to switch your OnceHub Account.

What happens if there’s an issue with the connection?

During a connection failure, ScheduleOnce Booking pages cannot accept bookings.This measure is taken to prevent the possibility of double bookings. 

In InviteOnce, you will not be able to invite to self-schedule or schedule on behalf.

To enable bookings, you must either restore the connection by reconnecting, or disconnect your calendar by clicking the Disconnect link and then reconnect again. Learn more about disconnecting a calendar

I cannot connect—what should I do?

This may be due to temporary communication problems with the Office 365 EWS API. Please try the following options:

  1. Make sure cookies are enabled on your browser.
  2. Verify that you can sign in to your Office 365 account.
  3. Try to connect again from your OnceHub Account. 

Learn more about troubleshooting Office 365 Calendar via EWS connection issues

If you’re still seeing issues, please contact us and we'll be happy to assist you.

Was this article helpful?
Thank you for your feedback!