I recently bought a Zenfone 10 and need to transfer my contacts, calendar, and messages from my old Nokia N900's nbu-type backup files. They are pretty extensive; the old phone dates from 2010 (it had a physical QWERTY keyboard, so I didn't want to give it up, but have no choice now), and there's over 600 contacts alone. I use both contacts as a database for information, and the calendar also as a historical database to keep track of dates for significant events.
I have managed to use Nokia's "PC Suite" to back up everything to a nbu (i.e., Nokia back up) file, so the transfer could be done from my laptop to the Asus without having to use the old Nokia phone.
So, it's not exactly like I have only have a handful of data to port over to the new phone. I think it would be weeks to just hand transfer the contacts alone.
Transferring data from an old Nokia phone with .nbu files to a new Asus Zenfone 10 can be a bit tricky, as Nokia's backup files (.nbu) are not natively compatible with Android devices. However, you can follow these general steps to transfer your data:
Note: Make sure you have a PC or a computer available for this process.
Backup Your Nokia Phone: