With flexi-passes, travel days always last 24 hours, but they also always begin and end at midnight, regardless of when in the day you catch your first train. After midnight, catching another train will initiate another travel day, but staying on one that you caught before midnight will not. The class of train - whether it’s a Railjet or a Night ICE - is irrelevant. So yes, you can travel overnight and only use one travel day, but only if you don’t change trains after midnight.

Hope this helps!

As @EdM  said if you board the Train before midnight everything fine as the day of depature counts. If you change after midnight trains it cause a new travelday :)

Maybe you say which Route you are talking about? For example for the Nighttrain Ljubljana - Munich you can buy for just 5€ a ticket to the first stop after Midnight and use from there your Railpass for connecting trains after Munich otherwise you would use 2 Traveldays of a Railpas

Before I used paper pass I just need one day for the night train after seven and I can transfer other trains the next day only put the next day date, now I have mobile pass but the same route I need to use two travel days? Does it make sense to consumers and treats us like an idiot!

So it is better to use paper pass for the night train because it saves a day for travelers 

No one answer my question if I use email to ask questions through my eurail pass

Hi Kevin, the night train regulation is the same for both paper Passes and mobile Passes. When travelling on a night train, you only have to write down the day of departure. For example, if you travel on a night train from 9 to 10 August, you only write down 9 August. If you're travelling with a mobile Pass, this will happen automatically once you add the journey to My Trip. If you added the departure date and do not change after midnight but it still says two travel days - can you share the route, so that we can look into it? 

On the day of departure of the night train, you can take as many trains as you want; it's on the same day after all. If you take another train after the night train has arrived, you'll have to use a new travel day.

Thanks for your reply but it seems you didn’t understand what my question is. 
I used to travel a lot with my paper eurail global pass first class. For example, if I leave Munich after 7:00 pm at night on September 14th, I will arrive in Hamburg at six in the morning on September 15th. I then can continue my trip to Denmark and Sweden by only writing down 9/16 on my paper pass. So from Munich on September 15 to Stockholm 16, I only use a one travel day, instead of two. Can you see what I mean.

ice 990 canceled and it broke my trip and cost me extra money to spend and I needed to put myself with so many homeless people around in Frankfurt central station at midnight. I am Asian traveling in Europe now during the pandemic. I told myself that I was not in Kabul airport so I just asked people to go away and leave me alone. 
it’s a lonely trip which I am taking so it’s good to have a talk with someone in the air.

lipeng

Three years ago I jumped on ice train departed from east station in Paris to Munich to avoid railway strikes in France. I saw some Chinese tourists crying because all their trip got destroyed and lost a lot of money and time. Finally it happened on me as well and funny is, the captain didn’t want to tell me anything about ice 990 cancellations because I am alien when I was on the train from Paris east to Frankfurt to catch the train to Hamburg which came from Munich.

I really don’t want to scream and yell those Germans who were hiding themselves behind the glass. I deserved it because I ran away from to look for trouble during the pandemic rampantly in Europe.

Hi, I do see what you mean. The night train (if not changing after midnight) still only costs one travel day. The only difference with what you are describing is that you should not write down the day of arrival of your night train but the train of departure. So all trains you take on the day of departure of your night train, are included in that one day that is counted. All trains (after the night train) that you take on the day of arrival will require you to take a second travel day, so two days in total.

There have been changes to the night train rule, so it used to be like in your situation, but that its now changed. Currently, When travelling on a night train, you only have to write down the day of departure, counting as one travel day (if you do not change after midnight). I trust this clarifies it. 

I am sorry to hear about your experience with train cancellations. You can best contact our Customer Support team here as they can assist you further. 

@Kevin Ho  the rule you describe is since 2020 History since 1.st January 2020 there is only the current day of depature rule :)

Yeah yet you need two traveldays on routes you needed before one but there even routes where you need yet one travelday instead of 2 before.

For example i was able to travel from Berlin via Brussels - London - York - Manchester - London - Caledonian Sleeper to Inverness with just one travelday started at 00:40 in Berlin arrival Inverness next day 8am :D

Thanks for your kind reply and the last time I used eurail pass to travel was in 2018. I think it’s quite important to let consumers know before they order passes. 
and it’s also important for to arrange my trip though eurail passes.

Eurail and Interrail advertised (back in 2019) on their website and the old Facebook groups the new rule and said few sentences below that the old rule is not in use anymore. In 2019 you could use both rules as exchange time and as said above since 2020 there is only the day of depature rules for trains

Now you can find on the offical pages of Interrail and Eurail only the actual Nighttrain rules For example at the bottom here 

or here https://www.eurail.com/en/help/interested-in-eurailing/what-is-a-travel-day