Is there a particular muhurta for doing kilan?
Dussehra and Diwali are the best muhurtas for kilan.
Related questions
In the main door picture, which were the jharokhas and which were the niches (aale)?
The small niches were made for lamps; they are the eyes of the door, and lamps placed in them open its eyes. The jharokhas beside them are the ears. Lamps must be lit in the niches on festivals such as Diwali, Dussehra, Holi and Raksha Bandhan, and in royal houses they were lit daily; a house whose eyes stay open keeps a right watch over everyone. If a door, even one in a wrong place, is decorated like this with small desi cow ghee lamps in the niches, its defects do not apply.
Do the swastiks for nazar and other uses need to be made at a particular time?
Select a muhurta if possible. Otherwise make swastiks for shanti and paushtik (peaceful, nourishing) work in the Chandra swar and for ugra (forceful) work in the Surya swar. Any remedy done in the wrong swar gives no result.
Does the time of offering matter when worshipping the devtas?
In a full vastu poojan all 45 devtas are worshipped and offered together. When one particular devta has to be activated, offer its bhog samagri or do its jaap in its own time slot for the maximum result. An offering at another time is not useless, but just as food eaten at the fixed time of hunger satisfies more, the result differs.
During Diwali puja the deity faces South and we face North. Is that right?
No, it is wrong. Seat the deity in the West facing East, and sit so that you look at the deity while your face is towards the North. The Lord's direction is what matters, just as the teacher's direction matters in a classroom.
From which corner should the kilan nails be fixed first?
From the South-East. Whenever nailing work is done anywhere, it is started from the South-East, not from the South and West or from the North and East.
How long is each Vastu Devta's time period, and when are Shikhi and Parjanya active?
Each outer devta has a sadhana period of 45 minutes, so the 32 outer devtas complete the 24 hours (32 x 45 minutes) and come back to the same point. Shikhi's period runs up to 3:00 am and Parjanya's from 3:00 to 3:45 am. Havan and offerings made in a devta's own period wake and activate it quickly.