After the Snana Purnima in Jyeshta month (May - June), there is no public darshan of Lord Jagannath and other deities at the Puri Jagannath Temple for 15 days. This 15-day period of no darshan at Puri Jagannath Temple happens before the Rath Yatra. There is a popular belief that Lord Jagannath during this period manifests as Alarnath Dev at Alarnath Temple in Brahmagiri, which is about 23 km from Puri.
After Snana Poornima, ritualistic bathing of the idols of Jagannath, there is a popular belief that the deities get fever. For a period of 15 day the deities do not appear before public. The deities remain in the Anasar house and appear a day before Puri Rath Yatra day.
During these 15 days, devotees visit the Alarnath temple at Brahmagiri in large numbers. Legend has it that Lord Jagannath manifests into the Alarnath Dev during the fortnight.
Thousands of devotees visit the temple during the period to have a darshan of Lord Jagannath as Alarnath Dev and to have the delicious Kheer bhog (Prasad) at the Alarnath temple.
Historians note that Sri Chaitanya Dev had visited the temple and it was the Holy Saint who had the vision of Lord Jagannath as Alarnath.
There is also an interesting ritual of offering the first copy of artistic compositions to Alarnath Dev by writers, poets and musicians.