What I think you are trying to do is difficult Lizzie. Folk Clubs, sessions, etc. are notorious for closing, changing venues, days of week, etc. without keeping anyone informed. Even people running local listings can have trouble keeping up with changes.

That was the big reason why we tried to link to mostly regional listings with our attempt at folkinfo. Even the listing pages come and go btw, without thinking about individual clubs.

Other attempts at providing this type of information I'm aware of include Martin Nail's listings and Jim Lawton's folkmap provides an interesting approach.