The next question is the first question.
I'm with gutonc; your original first question deserved the answer you received.
The revamp, however, is a fairer approach. This has been asked/answered multiple times in the forums, and a simple search will get you many threads.
The gist of it is - if you go into EM, you will work all sorts of shifts, at all times of day, on all days of the year. To us, the only days we don't work are the ones that don't end in a 'Y'
That being said, what's "less desirable" to you may be "more desirable" to me. I work 90% nights by choice, which frees up others in my group to work the shifts they want. Most groups will have some sort of holiday schedule, and/or differentials to get people into difficult-to-cover shifts.
You will work nights, you will work days, you will work when everyone else is sleeping and/or enjoying a 3 day weekend; but, you'll also only be working 10-15 days/month... I really like being off on Tuesdays; get a lot of things done because everyone ELSE is in some cubicle farm from 9-5. d=)
Cheers!
-t