Happy Tibb's Eve

"In jokes and plays four centuries ago, Tib often referred to a girl with loose morals, so there was no Saint Tib and therefore no Tib's Eve. To say something would happen on Tib's Eve was to say it would never happen...The phrase traveled to Newfoundland and Labrador. George Story describes Tibb's Eve as "generally 'neither before nor after Christmas', i.e. never" as an Anglo-Irish term in Newfoundland English dialect." https://en.m.wikipedia.org/wiki/Tibb%27s_Eve