As far as i can remember our Slug has always done 2 for 1 on all food on Monday - but i went today and they are doing 2 for 1 Curries on Tuesday now too.
I asked and its a national offer - its planned to be constant like the mondays offer (so the bar manager said !).
Two curries, chippatti & rice etc for about £6.
Just checked and its showing online too.