It started properly with Wrestlemania 14. Austin finally won the belt and his popularity really kicked off and D-X transformed the next night and became babyfaces and huge, most forget D-X really became popular AFTER HBK. I'd say it ended with Wrestlemania X-7, one of the best Wrestlemania's EVER. After that it was the Invasion.... But I'd say those are the timelines for the Attitude Era proper. Some say it started with Wrestlemania 13 though and Austin vs. Bret, but the "boom" business wise didn't get rolling 'til '98 for sure.