Storing other files on a Time Machine backup drive

I have a Time Machine backup disk, and I needed to find a way to copy some of my data into the 2TB free space on the disk.

There is a massive amount of misinformation about sharing the Time Machine disk space on the web. This question has been asked in this forum, too and no sensible answers were provided.

So here is how I did it, and it was much easier than I expected.

Luckily, my disk with Time Machine backups was AFPS formatted. I have no idea that afterthought sharing would work with other formats.

I loaded the Disk Utility App, The Edit menu of the app has the option of Partition, on the top and "Add AFPS Volume" further down. If you select "Partition" you will still get two options (Partition or add Volume). I have a good hunch partitioning would erase data but I might be wrong. In the next dialogue, I left the size options blank. I assume the OS decides the volume size as it's required. That's all there is to it: my Time Machine backups are kept as they were, and I copied my data to the new volume that was created. You need to quit Disk Utility so that you can eject the disk from Finder. By the way, my disk is encrypted, and that did not pose a problem