Swiss International Airlines - "Z" Business Class TATL Easter promotion

Hello all,

Does anybody know what is the cutoff date for Z Business Class fares between the USA and Europe in the first part of April ?

Is there and advance purchase requirement (2 months ?), a deadline, or can it be withdrawn at any time ?

Thank you.

All fares from any airline can be withdrawn at anytime for any reason.... the current promo for travel 1-14April as fare basis ZNC1S requiires 28 days advance purchase and a min stay of a saturday night