In Eastern Australia we are +10.

You are lucky if you are only displaying 24 hour time, and not the date,
or you need a full calendar all the way to checking leap years.
Just the one hour ahead the hour before midnight on a New Year’s Eve,
would make the entire date and day of week incorrect otherwise.

The calendar code I have posted here has done fine on that with my testing so far.
It is also the thing that tells you if any of it’s fields changed.