See: Diwali Muhrat Time 2011 This year Deepawali is on 26th October, 2011. A very large section of the Hindu society depends on astrology and adheres to the ideal time (muhurats) to perform the pujas and invest.

Diwali Muhrat Time 2009

Many Greetings for Diwali - New Year Festival.
Diwali is a festival of Hindus, but especially of the Businessmen, On this day they do puja of Account books and start writing their new accounts. This is called as "Chopda Pujan" or "Sharda Pujan" or "Muharat Pujan" meaning puja of account books. Chopda pujan is a day for everyone not only to reconcile one's financial books but also the spiritual books. People should pray to God to forgive us for all the mistakes this past year and to give the wisdom and strength to not make them the next year. 

The Shubh Muhurt (auspicious time) for Dhan Terash and Diwali Chopada Poojan this year Sumvat 2065.
Dhanterash : Dhanvantari/Dhan Poojan/Kuber Pooja  shall be performed on Thursday Oct 15 2009.
The best time for Dhan Poojan is

7.45AM-9.15 AM
12.15PM- 4.45PM
6.15PM- 10.45 PM

Laxmi Poojan/ Chopda Poojan: Diwali and Sharda Poojan/ Laxmi Poojan shall be performed on Oct 17 2009.There is Hasta/Chitra Nakshatra. yog on this day which is very good for Sharda Poojan ( Chopda Poojan/ Laxmi Poojan).
The best time for this purpose is

9.15AM- 10.45AM
1.45PM -6.15PM
7.45PM- 9.15 PM
10.45PM-2.15AM

The said Chopda Poojan/ Laxmi Poojan  can also be performed on Sunday morning 9.15AM-1.15PM
Labh Panchami/ Gyan Panchami falls on Friday 23 Oct. The best time for opening is 7.45AM to 12.15PM.

New Year falls on Monday 19th October. This is very auspicious day for performing Pooja and commencing new year business from 7.45AM- 9.15AM and 10.45AM-12.15PM.