On the night of Diwali at 1 am many devi devtay do ishnaan in the sarovar at Sri Harmandir Sahib. Only God knows how many bhagats, rishis, munis do tapp that day with greater efforts than other days. Das only knows that he has been told that Sant Gurbachan Singh ji bhindrenwale gave bachan that this day is considered special and that devtay do ishnaan at 1 am every Diwali.
Those who do kamai of whatever shabad that feels appropriate to get their iccha (desires) pooran (complete), will have that happen so long as they keep full sharda. Do abhyaas of whatever shabad seems appropriate from 8:30 pm to 1:30 am and do ardass for Guru Maharaj to fulilll your icha. If Maharaj does kirpa then you’ll get it.