I just got a new server from a server provider and he placed in some old 1.5TB HDD. They do support smartctl.
Is there a way I can findout how old these drives are?
If you want to know the HDD's manufacture date (e.g. for warranty issues) the only universal way to get that is to open the case and have a look at the HDD label.
Another possible way is to use
For example Seagate provides the warranty expiration date, which can be used to estimate the manufacture date if you know the length of the warranty period. The length of the warranty period usually depends on the model and you should be able to find it by searching the web.