Archanam is one of the nine forms of bhakti - devotion. Archanam includes the ritual of applying materials such as sandalwood paste, better known as chandan, on the Lord's murti or offering rice grains, flowers and leaves of sacred plants such as Tulsi (to Vishnu) Bili (to Shiva) and Ankado (to Hanumanji).
Since Archanam is a direct involvement with the Lord, the devotee experiences a more intimate fervor and spiritual contentment. Therefore people wedded to the path of Bhakti revel in Archanam as part of their worship rituals. In the Swaminarayan Sampradaya, chandan is smeared as a thick layer on the metallic murtis (Panch dhatu) during the hottest summer months, of Vaishakh and Jeth.
The murti of Shri Harikrishna Maharaj in BAPS mandirs is smeared with chandan and decorated accordingly, during this time.