The Muslim normally buka puasa - resume consumption of food and water - by 7.30 in the evening. The Bazaar Ramadan therefore will be very crowded from 4pm - 6pm. However if the stall is popular enough, and when it's weekend, you can expect the crowd to start coming in as early as 3 in the afternoon.
Just like this Popiah stall. When I reached the bazaar at 3.45pm, there was already a long line waiting. It's the same condition every year. Sometimes if you reach there late, you are likely to go home empty-handed.
Festive is big business here.