Details of the promotion are as follows:
The 4-day Swiss Travel Pass will have 1 extra travel day for free.
The 8-day Swiss Travel Pass will have 2 extra travel days for free.
The start date of the pass must be between 15 April and 13 November
2023. The pass is then valid for 5 or 10 consecutive days.
Unfortunately, this promotion is not as good as past promotions, which offered 25% off all days of the Swiss Travel Pass. But, this will benefit those needing a Pass for 5, 9 or 10 days.
With the past promotions, to get the discount, the Pass had to be purchased from one of the on-line sellers of the Pass. It was not available from the SBB website or app or in person at the train stations.