Not much of a paradox, but:
Numbers are infinite, and so are decimals. The decimal -4 hours, 59 minutes, 59.11 seconds- moves on to -4 hours 59 minutes 59.111 seconds-. If decimals are infinite, that number will continue to grow and grow. We are always in the same second.
I kind of made sense of it when it was said, but if you think about it for a few weeks straight it should come across as a paradox.