There are no direct trains that week due to engineering works in Denmark. Rail Planner hasn't been updated yet. Please do not use that app for planning, instead use bahn.com.

There are rail replacement buses for part of the journey but frankly I wouldn't recommend doing it during the night. You'll need 2 pass days too unless you pay for Copenhagen - Slagelse.

- IC København H - Slagelse 23:02 - 23:54

- Bus Slagelse - Fredericia 00:06 - 02:01

- IC Fredericia - Hamburg Hbf 02:21 - 06:26

Either you take daytime trains (+ bus) or a ferry like Trelleborg - Travemünde/Rostock (30% discount with the pass).

Thank you for your detailed advice 

I have a continuous 22 days pass, in that case, I don’t mind using 2 day passes

My ultimate destination is Amsterdam (to catch another Eurostar train, so I need to arrive before 2pm in Amsterdam on 28 July 2023) 

In this case, are there any fast but cheap routes to head from Copenhagen to Amsterdam?

Many thanks!

Also, why wouldn’t night replacement buses be a good idea? 

Why no night replacement buses? Comfort. Changing train-bus-train in a relatively small station in the middle of the night is nothing I’lld like… Most people like to sleep then.

I think you should leave earlier from Copenhagen, or try to leave the 27 from Jylland (Danish region that’s not an Island, cities as Vejle, Aarhus, Fredericia,...). Maybe a full day, because of track works it’s gonna take quite some time to get to Amsterdam. You don’t want to risk to miss your Eurostar. A small delay happens easily in Germany, which will lead you to miss Eurostar;

Use www.bahn.com to plan.

Which Eurostar are you taking ? 13:47 or 16:47 ? Have at least 2h margin in Amsterdam for delayed trains and passport control.

As Brendan advised, I'd leave Copenhagen earlier and stop en-route. Hamburg could be a great stop if you're taking the 16:47 train (departure at 8-8:45 am) or Osnabrück/Münster for the 13:47 (departure at around 7 am).

If you'd like to take an ICE train between Germany and the Netherlands, book it ASAP (3€ through ÖBB). Those trains are very popular. Seat reservation also very much recommended for the IC into the Netherlands.