I believe this is a bug on Rail Planner: perhaps you should update your app? Mine doesn’t say +1. It might be a bug related to timezones if you’re in NZ right now. I know that happened in the past…

Note that adding the train on Rail Planner isn’t needed to book seats. This step must only be done before boarding → it gives you a QR code which you present to staff (your “ticket”). I usually do it when I’m at the station.

For actually booking the seat reservations I’d recommend using Rail Europe (click on “add rail pass”) : no fees while eurail.com asks 2€ extra per person per train. You get a PDF which you’ll show onboard, or in the case of London Eurostar at the ticket gate before passport controls.

Hi! I’m having the same issue. My seat reservations are accurate as I booked them on the website. The Same trip has different lengths on the app the the website. The website is accurate and the app has +1 day added to it. As adding the train journey is needed to  use your train pass (10 travel days in two months) I’m worried that it’s going to count as two days instead of one. Is there a way to work around this so I only use one travel day?  

I'm pretty sure it's a bug due to timezones. (Hopefully the issue is solved soon) but anyhow it will work fine once you're in Europe.

As I said above, adding the train journeys is something you usually do at the last minute. Like at the station or when waking up. Plans can change, etc. -> once a travel day has started, it cannot get cancelled.

This is a bug and there are also many people complaining about it in various Facebook groups. Please report it to customer service here:

https://www.seat61.com/interrail-and-eurail-reservations.htm

Apparently, the workaround is to change to CET timezone but it should be needed to do that.