National Jack Day's documented footprint runs through holiday listings and dated social posts, with February 7 the better-attested date; one algorithmic aggregator instead derives an October 6 date from detected social-mention volume. No founder, organisation, proclamation or establishment record could be located.
A Canterbury manuscript, 1414
The History of the Monastery of St Augustine at Canterbury noted in 1414 that the English reshape names, turning Johannes into Jankin or Jacke. Scholars trace the chain from the Latin Johannes through Jehan and Jan. The English suffix -kin gives Jankin, which nasalizes to Jackin and then shortens.


