Yes, and no.
For initial surgery:
She had a CT scan late morning on the Wednesday.
Results 20 minutes later.
Blue lighted to a specialist hospital that afternoon.
MRI to get more precise imaging followed immediately by 6hrs of neurosurgery (ie they didn't wake her in between).
It was less than 24 hours from diagnosis to surgery.
But I suspect that was because they felt they needed to move that quickly with her.
She had some further surgeries which were also brought forward as emergencies, but more 'at the top of the list/moved to today' type of emergency, not a crash one, it that makes sense.
I think we were often the ones pushing other people down the queue tbh.
There were times though for more minor surgical procedures (she had 7 GA's in as many weeks) where we knew we were going to theatre that morning, and were gowned up and ready, for it to be a few hours later than anticipated.
Btw, if they give you a time estimate for surgery, add a couple of hours on, as sometimes it takes longer, and that doesn't mean anything has gone wrong.
Neuro wards can feel scary at first - but bear in mind that people can be in there for a thousand different reasons, and everyone's journey is different.
Even with my daughters tumour, she was in hospital for nearly 2 months and had every complication going, others with the same thing walked out within a week.