Google Announced that starting from January 07, 2018, Calender’s SMS notification will be no longer available. Even though its an essential feature for Calendar, you will still notify by in-app notifications.
Meaning G Suite users will get an in-app notification as well as email notifications.
Google Calendar made life easy when it comes to managing our schedule. The software fetches the date from others software like the time-date for movie show, traveling details and keeps it saving into Google Calendar.
After closing this function, you will notice below changes:
1. You will get emails instead SMS for new events, changes events, canceled events, or event responses.
2. When your Google calendar is open in mobile, then you will get event notifications in a web browser that has a calendar.
To support all of this changes, Google will also make necessary changes to Calendar API.
Source: G Suite Updates