On 16th Day of Lunar 5 Month (農曆五月十六日), it is considered as the Manifestation Anniversary of Heavenly Marshal Jiang Xian Guan (江府仙官).
For Year 2012, it falls on a Wednesday - 04 July.
For more info on Heavenly Marshal Jiang Xian Guan, you can proceed to the following links:
Bao Gao: http://javewu.multiply.com/photos/album/473/473
Fei Jie Fu Celebration 2011: http://javewu.multiply.com/photos/album/822