Re:Gee, thanks for the notice (Score 1)

It's rather that radars, ATC centers,... verify that information is not to old for display/use. As such, all equipment verifies different time sources (e.g.g internal clock, external GPS reference, DCF clock, etc)

With the addition of a leap second, you run the risk that some alarms will go off, indicating that there is a potential timing issue. This might cause the shutdown of certain systems.

Using NTP is not always an option: older systems cannot always connect to an NTP server (what with a 20 year old radar?), you need additional secured datalines, etc