The late nights and early mornings are usually only for course and on ex. I don't think that anyone in battalion (although I stand to be corrected) follows this routine in garrison.

Nevertheless, on course, it can be very demanding to stay alert, perform the physical tasks required of you, and practice good coursemanship when you are dog tired. Most people get used to it quickly, and it becomes a fact of life.

Don't underestimate the value of coursemates. When everybody is in the same boat and pulling together, it doesn't matter if you haven't slept in days; you'll get the job done. One more thing; everything looks better in hindsight. If you are lucky enough to have a good course, you will look back on it and your coursemates with fond memories and might catch yourself wishing you were back there (usually only the really insane think this way).

Good luck

On courses you have to keep in mind that some exercises are for teaching, and troops need to be well-rested even on the fourth or fifth day to be absorbing the new material you are delivering. Test exercises and unit training may have other objectives, but the bottom line is that rest routines are a basic and necessary part of field training.