Are stores closed on Dec 5 (Thai King's Holiday) in Bangkok?

Some of the smaller shops and stalls might be closed to celebrate the King's birthday, but the large malls and many restaurants, especially in the more touristy areas will be open. Most temples will be open, but unless you want to partake in the birthday celebrations you may want to avoid the the area around Sanam Luang in front of the Grand Palace and nearby areas where the birthday festivities take place, many streets are closed and often hundreds of thousands of people come to honor the King.