Munich to Budapest

Don't worry: if you can book a train, that train will be running.

Yes, that's just general information from the timetable database that is added to anything. If the train comes up on the specific date you searched, it will run on that date.

"Days of operation: not every day, 11. Apr until 6. Jun 2019" = This train runs on the day you have selected, and some other days between 11th April and 6th June. But it does not run every day, so don't assume it will run on any other day without checking that date.
We only sell tickets for trains which run.

Train times are fixed months in advance, and, in the case of international trains like this one, agreed between the railway companies involved (DB, ÖBB, MAV).

Do you mean 06:11 (morning) or 18:11? I looked on DB, and found a 06:11 on 30th April, arriving Budapest 13:19 with one change in Vienna, and an 07:11 with no changes arriving 14:19.
Both trains go via Salzburg and stop there. There is no advantage to going to Salzburg first, it is the same train.

Times and intermediate stops for the 06:11 trains:

Train RJX 265
München Hbf dep 06:11
München Ost dep 06:21
Rosenheim arr 06:53 dep 07:03
Salzburg Hbf arr 08:02 dep 08:08
Linz Hbf arr 09:14 dep 09:16
St.Pölten Hbf arr 10:00 dep 10:02
Wien Meidling arr 10:23 dep 10:25
Wien Hbf arr 10:30

Train EC143
Wien Hbf dep 10:42
Hegyeshalom arr 11:25 dep 11:28
Mosonmagyarovar arr 11:35 dep 11:36
Györ arr 11:53 dep 11:56
Tatabanya arr 12:29 dep 12:30
Kelenföld arr 13:02 dep 13:04
Budapest-Keleti arr 13:19

Thank you guys so much for helping me to understand that if I can book it...it will run.
Thank you, too, Chris F, for putting the schedule out there for me. As is turns out, I have booked the 07:-- arriving in Buda-K @13:-- with zero transfer in between.

We only sell tickets for trains which run.

In view of actual experience that's a rather bold statement. ;)

FYI, DB schedules have a pretty high standard for defining "every day" service. They tend to mean every day for an entire year's published schedule, such as 9 Dec 2018 to 9 Dec 2019. Many German trains and some other country and route schedules are published that regularly/invariably/unwaveringly and that far in advance, while others aren't.

In your example, the train probably follows the same schedule daily during the shorter period of 11 April to 6 June (or I see some 11 April to 15 May), but then changes a bit for a later block of time. On other routes, still-cryptic descriptions (relying on punctuation instead of words) might mention that a particular timing is operated on specific days of the week, or might link to a calendar view. But as stated by others, when you search for a particular date, you do get trains scheduled to run on that date.

Thats what? A 7 hour train ride? Unfortunately the discount carriers dont make that route and the big boys get $150 to $200 for a nonstop flight. I refuse to do a train for more than 4 hours and i hate 4. Me? I think i would work Vienna into the trip.

Hi,

If you want to get into Budapest at the earliest hour in the day, then the night train (EN) option is the way to do that.

Taking the EN night train from Munich will get you into BP prior to 9:30 AM the next morning. The night trains are a direct connection, whereas going by day requires you to transfer. I've done several routes by night train, from Munich too, ie Munich to Hamburg, Munich to Berlin , Munich to Düsseldorf, but not this one between Munich and BP specifically.