There are three prerequisites that must be met to accomplish a 1031 with complete non-recognition of capital gains.  One of which is that the time requirement must be strictly followed.

Under the regulations (Tax Reform Act of 1984), two time limitation periods have been imposed on deferred real estate exchanges: 1) Replacement property is required to be identified within a certain time, and 2) the replacement property should be received by the investor within a certain period of time. To successfully qualify for a 1031 exchange, both limitations should be satisfied. Otherwise, the replacement property will be treated as not like-kind to the relinquished property.

The identification period begins on the date you transfer the Relinquished Property and ends 45 days after. On the other hand, the exchange period begins on the date you transfer the Relinquished Property and ends on either the due date (including extensions) for your tax return for the taxable year in which the transfer of the Relinquished Property occurs or 180 after the due date (depending on which is earlier to occur).

Replacement Property is identified only if 1) it is designated as Replacement Property in a written document signed by the investor, 2) if it is unambiguously described (described by its legal description or street address ) in the written document or agreement.

The identified Replacement Property is treated as received before the end of the exchange period if 1) you receive the Replacement Property before the end of the exchange period, and 2), the Replacement Property received is significantly the same property as identified.

If it happens that in a deferred exchange, you have to transfer more than one relinquished property and have different transfer dates, the identification period and the exchange period are measured from the earliest date of which any of the properties were transferred.