Everyone agrees that the Feast of St Andrew is on November 30th.
What they disagree about is when November 30th is. :-)
In parishes following the Old Calendar, the Feast of St. Gregory the Wonderworker of Neo-Caesaria was commemorated. The dates are usually given in the following format, with the Julian (ecclesiastical date) first, and the Gregorian date second. So today would be listed as Nov 17/30.
Services for the Feast of St. Andrew in parishes following the Old Calendar will be on Nov 30/Dec 13.
It sometimes sounds complicated to people who have never lived with the Old Calendar, but it's not if you are living the liturgical life year in and year out. I lived with the Old Calendar for the first 9 years of my Orthodox life (Serbian first, then ROCOR), and personally loved it and miss it.
Two particularly nice side-benefits of the Old Calendar are that Thanksgiving virtually never falls in the Nativity fast, and that the Feast of the Nativity happens after all of the crass commercialism of "the holiday season" is long over.
"Everyone agrees that the Feast of St Andrew is on November 30th.
What they disagree about is when November 30th is. :-)"
Heretics! Heretics!
Oops, I mean Greeks! Greeks! :)