I guess as a Canadian I sort of straddle the middle. I hear "duty roster" all the time, unlike Helen, but I'd never heard rota before. So there's my two cents. (pennies...pence!?)

Regarding schedule: what's everyone's opinion on SK- versus SH- at the beginning? My dictionary lists both as correct. Is there a regional variation, or is it personal? I found that nuns and professors tend to say SH- and my friends and I usually say SK-.