Why these characters appeared?
These character could be appeared because of an Festival Update, and some times users by mistake enable this option.
How to remove Chinese characters from windows 10 calendar?
Follow the below steps which are shown in this video and you will be able to solve the problem easily in 1 minute or you can follow text answer given below.
First go to setting of windows, after that go to speech and time option [time option] inside this option there will be an option called “show additional calendar” choose “don’t show” option and Chinese characters will be removed. [Still Stuck No problem Watch video]