With the 'Mail and Calendar' app in Windows 10, you can sync your mail, calendar, and your contacts all in one place, using Google, Hotmail (Outlook.com) or iCloud account.
Recently, however, I've found that when I work with my iCloud account, the events in the Calendar app are delayed from 30 minutes to an hour, yes, it's so-called '1hour issue'.
For example, if you enter a schedule that starts at 9:00 AM, it's 9:00 AM in the Windows 10 Calendar app. The more interesting thing is that it is normally displayed on a mobile phone.
So I tried to change a lot of settings, but I did not find a solution to this problem, but I thought it was an account-related problem, so I tried to find the cause directly at iCloud.com.
And I found a clear cause, and of course there is a simple solution. :-)
The method itself is very easy. Here's how
The first thing you have to do is just visit iCloud.com and sign in!
Then select "Settings" in the bottom right Corner
Select 'Time Zone / Region' on the right side
This is the point of the problem. There are two main areas to choose from, it is important to match the contents of left and right. Especially, the time zone option on the left will be different from 'Seoul - Korea (Korea Standard Time)' or the area where you live.
Click on your location on the map and set it correctly. The right area must also be correct.
Then, after deleting your iCloud account from the Windows 10 Calendar app and re-registering, you'll see that all of your schedule times are back to normal :-)
It's easy, huh?!