Orchard Road not crowded

I just came back from Orchard Road and guess what? Tonight is really empty. I wonder what other events are on? Is it the air show? I went to major shopping malls and the crowds is very good! Even with tonnes of sales going on but the queue at the cashier is very short! In fact, when I was in Isetan, there are no customers at the cashier when I paid up. I was 2nd over at Tangs. The walkway is also not crowded and easy to walk. The traffic is smooth. In fact, it is something like a weekday. Is it due to ERP also? Whatever it is, I feel tonight is a freak weekend for Orchard Road.