The system time is displayed on the right side of the Win10 taskbar. The default format is “hour: minute”. How can I display “seconds”? In the Windows 10 first anniversary update and subsequent versions, following the IT home to modify the registry allows the system time display to be accurate to the second.Specific steps are as follows:1. Enter regedit in the Cortana search bar and press Enter to enter the Registry Editor.2. Position to:HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced3, create a new DWORD (32-bit) value , named ShowSecondsInSystemClock4, modify the numerical data to 15, restart explorer.exe .

To change back to the default settings, simply delete ShowSecondsInSystemClock and restart the file explorer.

This is just interesting ideas…there is no big use of adding second in time..but you can apply and check how it work.