When we talk about Vastu for construction, it should be kept in mind to begin construction only during special periods according to the Hindu calendar like Phalgun (February 14 to March 13), Vaishaka (April 14 to May 13), Sharavan (July 14 to August 13). These dates are considered to be productive for the welfare of the family. The rest of the year is not well regarded at all. Many dire warnings are issued to dissuade people from beginning construction then.
Additionally, all construction ventures should be commenced only when the moon is waxing and not waning. The symbolism here is that during this time things are growing towards fullness and completion; after the full moon, it’s a; downhill, so to speak. Days 2, 3, 5, 6, 7, 10, 11 and 13 of the waxing moon (in other words, days since the new moon) are considered extremely fruitful.
Each day of the week also has certain qualities that impact the appropriateness of beginning construction then.
• Monday begets happiness and prosperity if work is begun then
• Tuesday is inappropriate and ill fortune will befall on the owner
• Wednesday leads to material gains and joy.
• Thursday ensures long life and happiness with children that make you proud
• Friday brings peace of mind and progress in one’s work
• Saturday is popular in the state of Rajasthan as a day to begin work
• Sunday, like Tuesday, is inappropriate, and ill fortune will befall you
As additional point to keep in mind is that blue moon months- those with two full moons- are to be avoided as times in which to begin construction.
The griha-pravesh or entry into the new house has a similar set of auspicious times. A cardinal rule is that one should never have a house warming, lock up the new house, then go back to the old house, and slowly move in stages, as is convenient. Either begin inhabiting the new house immediately or defer the ceremony.
The griha-pravesh is divided into three parts- for new houses, for re-entering your house after long travels or pilgrinages and for entering your house after a major renovation. The best months to move into a new house are:
March (January 14 to February 13), Phalgun (February 14 to March 13), Vaishaka (April 14 to May 13) and Jyeshtna (May 14 to June 13). However, the month of Kartik (October 14 to November 13) can be resorted if the need in pressing.
Tuesday, Saturday and Sunday are ruled out as inappropriate times for entry into the new house. Days 1, 2, 3, 5, 7, 8, 10, 11, 13 and 15 of the waxing moon are beneficial. It is best to enter the house in daylight.
To move back into a renovated house, a slightly different set of rules apply. The appropriate months are expanded now in this order of preference:
Karthik (October14 to November 13), Shravan (14th July to 13th August), Magh (14th January to 13th February), Phalgun (14th February to 13th March), Vaishaka (April 14th to May 13th) and Jyeshtha (May14th to June 13th)
Sunday and Tuesdays are to be avoided as days to enter the house. The dates of the waxing moon cycle remain the same.