damn thats painful... my boss has been on my back for a whole month trying to get me to tell her when im able to work. so she just went ahead and made the roster for the next month and has put me on during the times i was hoping to get allocated to
not happy jan.
ty for your help ninwa. your great. 
You've had a whole month to say when you're able to work. You nearly always get your first preferences. You could have given your work a rough guideline.
Ie I told mine near the end of january my availability is likely to be such and such but I can only confirm it on the 24th feb and tuesday and thursday might change a bit in when I can start.
There is no way I would leave work hanging and tell them after the roster is done that 'oh i can't work then i has lecture', when you have known about that for over a month.
Well, aren't you special. Perhaps you should spend less time tooting your own horn about how awesome you are notifying the place where you work (lol, a job of HEIGHTENED RESPONSIBILITY I might add) and more time helping shona instead. Not castigating her for a mistake she made without the knowledge that "you almost always get your first preference". Something someone who has seen how Allocate+ works for 2 semesters would know. Not a first year who has no idea and is afraid of misleading her employer.
Nice work there, genius.
Re: Shona, what happypuff was trying to say in a highly unnecessary, self-promoting, and snarky tone, is that you should give them the times you hope to be free. At the same time you should tell them that these times are not final but it should be a rough guideline.
I'd also apologise for the delay, but then explain that you were worried about giving them the wrong times, and then having to reverse them a few weeks later because you weren't sure how reliable the Monash timetabling system was.
I'm sure they'll understand.

Good luck.