Only as information, I found how the AI works:
That specific statement: “Swiss Portion of the Journey: For the part of a Nightjet journey that is within Switzerland and falls within the GA Night’s hours of validity (7 PM - 5 AM/7 AM), your GA Night covers the basic travel fare in 2nd class (equivalent to a seat)” is a synthesis of information found on the official SBB (Swiss Federal Railways) website regarding the GA Night travelcard and general principles of how Swiss travelcards apply to international trains.
Here’s a breakdown of where the components of that statement come from:
GA Night Validity (Area, Time, Class):
The official SBB pages for the GA Night Travelcard (also formerly known as seven25) clearly state that it allows free travel in 2nd class within the GA travelcard area of validity (which includes the SBB network and many other Swiss transport companies).
These pages also specify the hours of validity: 7 PM to 5 AM on weekdays, and 7 PM to 7 AM on Saturdays, Sundays, and national public holidays.
Sources for this include (from previous searches):
SBB Website: “Night GA Travelcard – the young persons’ travelcard for night owls” (sbb.ch)
SBB Website: “Hilfe zum GA Night” / “GA Night – das Jugendabo für Nachtschwärmer:innen” (sbb.ch)
BLS Website (which also sells and describes the GA Night in line with SBB): “Travelcard - GA Night - BLS Ltd.” (bls.ch)
Application to Nightjet Trains (Swiss Portion):
Nightjet trains, when operating within Switzerland, use the same network covered by the GA travelcard area of validity.
The principle for Swiss travelcards like the GA (and by extension, the GA Night during its specific validity times) on international trains is that they cover the Swiss domestic leg of the journey.
The Nightjet website (nightjet.com, operated by ÖBB) under “General Information” / “Tariff Information” also mentions that Swiss discount cards like the “SBB half-price subscription (SwissPass, Halbtax-Abo)” entitle users to a discount for trips from/within Switzerland, which supports the integration of Swiss travelcards into Nightjet pricing. While it doesn’t explicitly detail the GA Night, the GA family of products works on the principle of covering the fare on the GA network.
“Basic travel fare in 2nd class (equivalent to a seat)”:
The GA Night is a 2nd class travelcard. Therefore, any travel it covers would be for a 2nd class fare.
On Nightjet trains, a reservation is always mandatory, and there are different comfort categories (seat, couchette, sleeper). The GA Night covers the travel fare component for the Swiss section, which, in its most basic form on a night train, would be equivalent to the right to occupy a 2nd class seat (even though you’d still need to pay the separate mandatory seat reservation fee for the Nightjet).
It explicitly does not cover the supplements for higher comfort categories like couchettes or sleepers, nor does it cover the mandatory reservation fee itself. This is standard for most rail passes when used on premium services or night trains that require such add-ons.
Therefore, the statement you quoted is a logical conclusion derived from combining the official rules and scope of the GA Night with the way Nightjet services operate in conjunction with national rail passes. No single sentence on an SBB or Nightjet page might phrase it exactly like that in one go, but the individual components and the underlying logic are based on their official information. When booking a Nightjet ticket and declaring a GA Night, the system should calculate the price by deducting the value of the Swiss travel portion covered by the GA Night.
