[piquadrat]

I heard numbers of 45 minutes less for Zurich-Milan. Maybe your number already includes the Ceneri Base Tunnel[1], to be opened in 2020?

[1]: https://en.wikipedia.org/wiki/Ceneri_Base_Tunnel

[MagnumOpus]

Indeed you are right - I got my number from 24heures.ch, and it is comparing the number before both tunnels vs. the time after both are open:

http://www.24heures.ch/suisse/Le-tunnel-de-base-du-Gothard-r...