There are some dates on the calendar that people don't want to miss, and for horsemen and patrons in California, one of them is opening day at Del Mar.The 43-day meet, which this year begins Wednesday, July 18, is often considered the jewel of California racing. One of the selling points of the track is that it's nestled along the coastline with sweeping views of the Pacific Ocean. But management said atmosphere really hasn't been enough to lure big crowds.In recent years, Del Mar has used promotional events to lure tourists or one-time visitors. The implemented a later post time on Fridays, and rock and jazz concerts after the races. This year, acrobats from Cirque de Soleil were scheduled to perform opening day in the paddock area after the horses are led to the track."We have to market Del Mar more than just a racetrack," said president and general manager Joe Harper, who joked that he needs to revisit the track's insurance policy before the show. "If you are going to throw a party, you have to entertain guests."Besides the opening day festivities, Del Mar will have special theme weeks during its summer meet, which concludes Sept. 5. "One week, it will be for families with face-painting and pony rides for the kids," Harper said. "Another week will be devoted to extreme sports, where people can rock climb."On the racing side, there will be more than 27 stakes worth more than $6 million. The featured event, the $1-million Pacific Classic (gr. I), will be run Aug. 19.