Day 45 is when the replacement property has to be named in writing. Day 180 is when you have to close on it — or your federal return due date for that year, if that comes first. Enter one date below to see both.
Both clocks start on the day title transferred — usually your closing date, not the day you signed the contract. It is on your settlement statement. Tax rules call the property you sold the relinquished property.
Pick a date to see your day-45 and day-180 dates.
The transfer date is Day 0. The calculator adds 45 and 180 calendar days to that date; it does not assume a tax-return due date.
For this example, a March 2, 2026 transfer produces an April 16, 2026 identification date and an August 29, 2026 day-180 date. The actual exchange period ends on the earlier of day 180 or the due date of the federal return for the year of the sale, including extensions. Because this calculator does not ask for that return due date, it shows the standard day-180 date and tells the user to confirm the earlier-of rule separately.
The two periods run at the same time. Day 45 does not start a second 180-day clock.
A deferred exchange needs the qualified intermediary and exchange documents in place before the relinquished-property sale closes. At closing, the exchange proceeds go to the qualified intermediary rather than to the seller. The sale date is Day 0 for both calculations.
Use the closing statement to confirm the transfer date, then ask the qualified intermediary to confirm the two calendar dates. The calculator is a second view of that arithmetic, not the transaction record.
The replacement property must be identified in writing within 45 calendar days. The identification is signed by the taxpayer, delivered to the qualified intermediary or another permitted party to the exchange, and describes the property clearly enough to identify it.
Weekends and holidays count. Once the identification period ends, the list is locked: a property cannot be added, substituted, or revoked after Day 45. The transaction can close before Day 45, but the identification requirement still applies.
The replacement property must be received by the end of the exchange period. The standard date is 180 calendar days after the relinquished-property transfer, but the period ends sooner when the federal return for the year of the sale is due sooner, including extensions.
A purchase contract is not the same as receiving the replacement property. The linked timeline follows the closing, reporting, and earlier-return-date steps in order.
If no replacement property is identified by the end of Day 45, the exchange fails and the qualified intermediary returns the proceeds. After Day 45, a closing on property that was not on the identification cannot repair the list.
If the replacement property is not received before the exchange period ends, the deferred exchange fails. The gain can become taxable for the year of the sale. Transaction facts, relief notices, and return dates can change the analysis, so confirm a missed or disputed deadline with the qualified intermediary and tax adviser.
Read the 1031 exchange timeline for the same Day 0, identification, closing, and return-reporting sequence with the actions before and after each deadline.