RFC 4880 says that the Literal Data Packet's time stamp is four octets long. Listing packets shows that it is five octets long, at least in GnuPG 2.2.6.
The time stamp comes after the word "created", and is comprised of digits 0 to 9. How can it be read?
:literal data packet: mode b (62), created 1562530941, name="My File"