Why did Apple receive a reminder about the Gregorian calendar?

There are technical problems, user misoperation, and malicious attacks that cause Apple to receive a reminder of the Gregorian calendar.

1. Technical problem: Due to a technical failure or loophole, Apple's calendar application received a reminder of pornographic content. This situation is rare, but it is not impossible.

2. User misoperation: A user accidentally added pornographic content to his calendar and shared it with others. This situation may be accidental or intentional.

3. Malicious attack: Someone deliberately sends pornographic content reminders to Apple users in an attempt to interfere with their lives or obtain their personal information. This situation is dangerous, so users need to be vigilant and take necessary safety measures.