How to close Apple's mobile phone calendar and receive spam?

How to close the calendar when it receives spam, as follows:

Open the calendar App, click "Calendar" at the bottom to enter the subscription page, click the exclamation mark behind the personal/work calendar, close the "Schedule Reminder" and delete the calendar. Open the settings, click on your Apple ID account, then enter the iCloud page, find the calendar option, and turn off the calendar iCloud synchronization switch.

A brief introduction of the calendar is as follows:

A calendar is a daily publication that records dates and other related information.

Each page displays one day's information as a calendar, one month's information as a monthly calendar, and one year's information as an annual calendar. There are many forms, such as calendars, desk calendars, calendar cards and now electronic calendars.

The first calendar in China was about 4000 years ago. According to a page of Oracle bone calendar in Oracle Bone Inscriptions, it is proved that the calendar of Yin Dynasty has reached a considerable level. This page of Oracle Bone Inscriptions is the oldest calendar in the world, also called the calendar.

Then, historians combined the contents of the calendar with the events in the imperial court and China, refined them, recorded them and became national history. Later, because the calendar brought a lot of convenience to life, it gradually entered the families of many senior officials in North Korea. After some changes, it was compiled into its own calendar.

Later, with the development of popular calendars and family calendars, people printed calendars with lunar calendars, solar terms and auspicious days, leaving a large blank for keeping records.