Why is that bad? Please enlighten a naive hacker

If you convert this to Unix epoch time (Seconds since 1970-01-01 00:00:00), the result will be -1.

Which is problematic in several scenarios: - Databases which store dates in integer fields and maybe don't handle negative values. - Other overflows unhandled by date parsers - Libraries, which use -1 as 'invalid'.

I love how I learnt a real hacker titbit from an age poll.