Exemption u/s 54

Dear All
Exemption u/s 54 is available for purchase of residential house 1 year before and 2 years after from the date of transfer of a residential premises. What is date of transfer in this context? Is it sale deed registered, possession letter, payment proceeds??
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In the case of sale of immovable properties, the sale can be said to have taken place on the date of execution of the sale deed and not on the date of the agreement to sell.

- Hall & Anderson (P.) Ltd. v. CIT [1963] 47 ITR 790 (Cal.)/CIT v. F.X. Periera & Sons (Travancore) (P.) Ltd. [1990] 184 ITR 461 (Ker.)/CIT v. Ghaziabad Engg. Co. Ltd. [2001] 116 Tax man 268 (Delhi).

Also purchase of residential house in under construction building is allowed for exemption u/s 54.
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Where the assessee sold a flat, and within two years entered into an agreement for the purchase of a new flat which was under construction, and paid the amounts in installments within three years of the sale of the earlier flat, exemption is admissible

- CIT v. Smt. Bharati C. Kothari [2000] 244 ITR 352 (Cal.)

If yes what is the date...date of registration, possession, payment made in advance before possession and registration?
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For the purpose of section 54, the date of agreement to purchase should be taken as the date of purchase and the date of registration of sale deed for purchase is not relevant

- CIT v. R.L. Sood [2000] 108 Tax man 227/245 ITR 727 (Delhi).