[tz] macOS implements Links with file copies?

[Guy Harris]

On Feb 12, 2021, at 4:56 PM, Deborah Goldsmith <goldsmit at apple.com> wrote:

> /var/db/timezone/zoneinfo is also a soft link:
> 
> % ls -l /var/db/timezone/zoneinfo 
> lrwxr-xr-x  1 root  wheel  38 Feb  8 21:00 /var/db/timezone/zoneinfo -> /var/db/timezone/tz/2021a.1.0/zoneinfo

So how many /var/db/timezone/tz/{version} tzdbs are kept around?

	$ ls /var/db/timezone/tz
	2020d.1.0	2020f.1.0	2021a.1.0

And why are older versions kept around?