Booking two same train/journey on the same travel day

Hi there,

I am using a eurail pass this week. I have a bunch of trains to take, so I am unsure I’ll be able to be on time for each train. For this reason, I wish to add the same journey to the same travel day, but with different time schedules. These are all trains without seat reservation. For example, I wish to add, on the 22th of June, two trains travelling from Stuttgart Hbf to Muenchen Hbf, at 17h15-19h13 AND 18h14-2026. As I arrive à Stuttgart (train with a seat reservation) at 17h04, I am not sure to be able to get the 17h15.

So I wonder : is it possible to add these journeys simultaneously before the day of travel ? If so, what happens for the train ticket I did not use ? If not, is it possible to add a second journey (same travel destination but different time) on the day of travel (after missing a train, for example) ?

I hope this is readable !

Thank you so much,

Amélie