(tap questions to expand the answers)
Why would I need ClockSync, Android already has Automatic setting for Date& time?

Why do I get "Can't connect to NTP server" error?

Why does ClockSync need root to work?

What is Rootless Mode?

What is "Ignore setCurrentTimeMillis result" option for?

Why does ClockSync start on boot?

Why do I get incorrect time or zone after sync?

What is NTP?

Why don't you use GPS time, it's much more precise and doesn't require network connection?

What does the "Restore permissions" option actually control?

Automatic synchronization doesn't work properly, why?

What is "Strict interval" option for?

How does "High precision" mode affect automatic synchronization?