1031 Exchange Deadline Calculator and Timeline Worksheet
A 1031 exchange runs on two clocks that both start the day you transfer the property you sell: you must identify replacement property by midnight of the 45th day afterward, and receive it by midnight of day 180 or your tax return’s due date for that year (with extensions), if that comes sooner. Count calendar days, with the closing date as day 0. Neither the statute nor the regulation adds time when a deadline lands on a weekend or holiday, and exchange companies treat both dates as fixed.
This page is a paper calculator. It gives the counting rules, a lookup table of 2026 closing dates with both deadlines already worked out, three hypothetical examples, and a task list for each window. The rules for what a valid identification looks like are on our 1031 identification rules page, and the overall structure is in our 1031 exchange guide.
The rules behind the dates
Internal Revenue Code section 1031(a)(3) treats replacement property as not like-kind if it isn’t identified “on or before the day which is 45 days after” the transfer, or if it is received after the earlier of the 180th day or the due date, “determined with regard to extension,” of the return for the year of the transfer.
Treasury Regulation 1.1031(k)-1(b)(2) puts the same rule into periods. Under the regulation, the identification period starts when you transfer the relinquished property “and ends at midnight on the 45th day thereafter.” The exchange period begins on the same date and ends at midnight on the earlier of the 180th day or the return due date, including extensions.
| Deadline | Counted from | Ends | What must happen |
|---|---|---|---|
| Identification period | Transfer of the property you sold | Midnight, day 45 | Signed, written identification delivered to the proper party |
| Exchange period | Same date | Midnight, day 180, or the return due date with extensions if earlier | Replacement property received |
The periods run at the same time; the 45 days are part of the 180, not added to them. If you sell more than one relinquished property in the same exchange on different dates, the regulation measures both periods from the earliest transfer.
How to count the days
- Find the transfer date. For most sales this is the day the sale closes and the deed records. Get the date from your escrow officer’s closing statement, not from the contract.
- Call that date day 0. The next calendar day is day 1. The regulation’s own example shows the method: a transfer on November 16, 1992 has an identification period ending at midnight on December 31, 1992.
- Count 45 and 180 calendar days. Weekends and holidays count. Use the table below, or count the days left in each month.
- Check the return due date. If day 180 falls after your return’s due date, the exchange period ends on the due date unless you extend the return.
- Move your own target earlier. If a deadline falls on a weekend or holiday, deliver the identification or close the purchase on the last business day before it.
What about the general weekend rule? Internal Revenue Code section 7503 lets some tax acts, such as filing a return or paying tax, be done on the next business day when the deadline falls on a Saturday, Sunday or legal holiday. Exchange companies don’t apply it to these periods. IPX1031, a qualified intermediary, states that the 45-day and 180-day periods cannot be extended even if the last day is a weekend or legal holiday. Don’t count on a next-business-day rule; confirm your dates with your QI and CPA.
2026 lookup table
Find the closing date in the first column that is on or just before yours, then add the same number of days to both deadlines. For example, a closing on May 8 is seven days after May 1, so its deadlines are seven days after the May 1 row. The last column assumes a calendar-year individual whose 2026 return is due April 15, 2027.
| Sale closes (day 0) | Day 45: identify by midnight | Day 180 | Return due date ends the period first? |
|---|---|---|---|
| Thu Jan 1, 2026 | Sun Feb 15, 2026 | Tue Jun 30, 2026 | No |
| Thu Jan 15, 2026 | Sun Mar 1, 2026 | Tue Jul 14, 2026 | No |
| Sun Feb 1, 2026 | Wed Mar 18, 2026 | Fri Jul 31, 2026 | No |
| Sun Feb 15, 2026 | Wed Apr 1, 2026 | Fri Aug 14, 2026 | No |
| Sun Mar 1, 2026 | Wed Apr 15, 2026 | Fri Aug 28, 2026 | No |
| Sun Mar 15, 2026 | Wed Apr 29, 2026 | Fri Sep 11, 2026 | No |
| Wed Apr 1, 2026 | Sat May 16, 2026 | Mon Sep 28, 2026 | No |
| Wed Apr 15, 2026 | Sat May 30, 2026 | Mon Oct 12, 2026 | No |
| Fri May 1, 2026 | Mon Jun 15, 2026 | Wed Oct 28, 2026 | No |
| Fri May 15, 2026 | Mon Jun 29, 2026 | Wed Nov 11, 2026 | No |
| Mon Jun 1, 2026 | Thu Jul 16, 2026 | Sat Nov 28, 2026 | No |
| Mon Jun 15, 2026 | Thu Jul 30, 2026 | Sat Dec 12, 2026 | No |
| Wed Jul 1, 2026 | Sat Aug 15, 2026 | Mon Dec 28, 2026 | No |
| Wed Jul 15, 2026 | Sat Aug 29, 2026 | Mon Jan 11, 2027 | No |
| Sat Aug 1, 2026 | Tue Sep 15, 2026 | Thu Jan 28, 2027 | No |
| Sat Aug 15, 2026 | Tue Sep 29, 2026 | Thu Feb 11, 2027 | No |
| Tue Sep 1, 2026 | Fri Oct 16, 2026 | Sun Feb 28, 2027 | No |
| Tue Sep 15, 2026 | Fri Oct 30, 2026 | Sun Mar 14, 2027 | No |
| Thu Oct 1, 2026 | Sun Nov 15, 2026 | Tue Mar 30, 2027 | No |
| Thu Oct 15, 2026 | Sun Nov 29, 2026 | Tue Apr 13, 2027 | No |
| Sun Nov 1, 2026 | Wed Dec 16, 2026 | Fri Apr 30, 2027 | Yes: Thu Apr 15, 2027 unless extended |
| Sun Nov 15, 2026 | Wed Dec 30, 2026 | Fri May 14, 2027 | Yes: Thu Apr 15, 2027 unless extended |
| Tue Dec 1, 2026 | Fri Jan 15, 2027 | Sun May 30, 2027 | Yes: Thu Apr 15, 2027 unless extended |
| Tue Dec 15, 2026 | Fri Jan 29, 2027 | Sun Jun 13, 2027 | Yes: Thu Apr 15, 2027 unless extended |
Dates were counted day by day and the weekdays checked against the 2026 and 2027 calendars. Some rows start on a weekend or holiday only to keep the table regular; your own closing will almost always be a business day. Have your qualified intermediary confirm your dates in writing.
The return due date trap
The exchange period ends on the earlier of day 180 or your return’s due date with extensions. IRS guidance says calendar-year individuals file by April 15 and can get an automatic six-month extension by filing Form 4868 by the original due date. For a 2026 sale, that original date is Thursday, April 15, 2027.
Count back 180 days from April 15, 2027 and you reach October 17, 2026. So for a calendar-year individual, any 2026 sale that closes on or after October 18 has an exchange period that ends on April 15, 2027 unless the return is extended. Ask your CPA to file the extension before April 15 and to hold the return until the replacement has closed, so Form 8824 can be completed.
The regulation’s example makes the same point. A calendar-year corporation that transferred property on November 16, 1992 had an exchange period ending March 15, 1993, its return due date, but if it obtained the automatic six-month extension, the period ran to May 15, 1993, the 180th day. LLCs taxed as partnerships, corporations, trusts and fiscal-year filers have their own due dates, so check yours rather than relying on April 15.
An extension of time to file is not an extension of time to pay, the IRS notes, so your CPA may still want an estimated payment by the original date.
Three hypothetical examples
These examples are invented to show the arithmetic. They are not client transactions.
A June closing with a holiday-season deadline
A Santa Rosa duplex sale closes Tuesday, June 30, 2026. Day 45 is Friday, August 14, 2026. Day 180 is Sunday, December 27, 2026, two days after Christmas. The return due date doesn’t matter because April 15, 2027 is later. Because county recorders and many lenders don’t work on Christmas or the weekend, the practical target is to close the replacement by Thursday, December 24, and the safer target is mid-December.
A late-October closing that needs an extension
A Napa rental sale closes Friday, October 30, 2026. Day 45 is Monday, December 14, 2026. Day 180 is Wednesday, April 28, 2027, but the owner’s 2026 return is due April 15, 2027. Without an extension the exchange must be complete by April 15; with a timely Form 4868 extension, it runs to April 28. Using the same method, a November 2, 2026 closing gives a day 45 of December 17, 2026.
A year-end closing and a weekend day 45
A Sonoma County commercial building sale closes Wednesday, December 30, 2026. Day 45 is Saturday, February 13, 2027, so the identification should be delivered by Friday, February 12. Day 180 is Monday, June 28, 2027. That is more than two months after the April 15, 2027 return due date, so without an extension the owner would lose 74 of the 180 days.
Timeline worksheet
| When | Task | Your date |
|---|---|---|
| Before the sale closes | Sign the exchange agreement with your qualified intermediary so sale proceeds go to the intermediary, not to you; start touring replacements | |
| Day 0 | Get the recorded transfer date from escrow; write day 45 and day 180 on your calendar and the intermediary’s | |
| Days 1 to 30 | Narrow the candidates, make offers and get the primary target under contract with contingency dates well before day 180 | |
| By day 40 | Prepare the written identification with street addresses or legal descriptions; decide which identification test you are using | |
| By day 45, midnight | Sign and deliver the identification; keep proof of delivery. Revocations and changes must also be in writing before this deadline | |
| Days 46 to 150 | Remove contingencies, arrange financing and confirm the intermediary can fund on time | |
| Before April 15 if your period crosses it | Have your CPA file an extension and hold off filing the return | |
| By day 180, or the due date if earlier | Close on the replacement property | |
| Tax return | Report on Form 8824: line 5 is the date of written identification, line 6 the date you received the property |
For choosing an intermediary, see our qualified intermediary guide. Diamond may refer you to partners we work with; you’re free to choose any provider. If you need to buy before you sell, a reverse exchange uses its own timing rules, and building on the replacement property within the 180 days is covered in our improvement exchange guide.
Disaster postponements
The deadlines don’t stretch for market conditions or a slow escrow, but they can move after a federally declared disaster. Revenue Procedure 2018-58 names both section 1031(a)(3) periods, identification and exchange, in its list of time-sensitive acts that the IRS may postpone. The IRS issues a notice or news release for each disaster that defines the affected taxpayers, the covered area and how long the relief lasts.
As of October 24, 2026, the IRS disaster relief page lists no California announcements for 2026. Its most recent California entry is the 2025 wildfire relief, announced in IR-2025-10, which postponed various deadlines to October 15. If a fire, flood or storm hits during your exchange, ask your intermediary and tax adviser to confirm in writing whether the relief covers you and your property before you rely on it.
Questions people ask
When does the 45-day clock start in a 1031 exchange?
On the date you transfer the property you sold, usually the closing date. That date is day 0, and the identification period ends at midnight on the 45th day after it.
Is the 180 days in addition to the 45 days?
No. Both periods start on the same date, so you have 45 days to identify and 180 days in total to close, not 225.
What if day 45 or day 180 is a Saturday, Sunday or holiday?
Neither section 1031 nor the regulation provides a weekend or holiday extension, and the intermediary IPX1031 says the periods can’t be extended even when the last day is a Saturday, Sunday or legal holiday. Finish on the last business day before it and have your intermediary confirm the date.
Why might I have less than 180 days?
Because the exchange period ends on your tax return’s due date if that comes first. For a calendar-year individual, 2026 sales closing on or after October 18, 2026 run into April 15, 2027, so file an extension to keep the full 180 days.
Does filing an extension really add time to my exchange?
Yes, up to day 180. The statute measures the due date “with regard to extension,” and the regulation’s own example shows an automatic extension carrying the exchange period from the return date to the 180th day.
Can the IRS extend my 1031 deadlines?
Only in narrow cases, mainly after a federally declared disaster under Revenue Procedure 2018-58. The specific IRS notice for that disaster decides who qualifies and for how long.
I sold two properties on different dates. Which date counts?
The earliest. When several relinquished properties in the same exchange are transferred on different dates, both periods are measured from the first transfer.
This is general information, not tax or legal advice. Your intermediary and CPA should confirm your exact deadlines, your return due date and any extension in writing before day 1 of the exchange.
California has its own reporting for exchanges into out-of-state property, covered in our FTB 3840 clawback guide, and cash taken out of an exchange is explained in boot and partial exchanges. Vineyard and ranch owners should also read 1031 exchanges for vineyards and ranch land.
If you’ve just closed a sale or are about to, and you need replacement property found and under contract inside these windows, talk with Diamond’s investment team. The clock is short, so contact us before closing if you can.
Sources & notes
- Cornell Legal Information Institute: 26 U.S. Code section 1031
- Cornell Legal Information Institute: Treasury Regulation 1.1031(k)-1 (deferred exchanges)
- Internal Revenue Service: Instructions for Form 8824 (2025)
- Internal Revenue Service: When to file (individuals), updated May 22, 2026
- Internal Revenue Service: Revenue Procedure 2018-58
- Internal Revenue Service: Tax relief in disaster situations
- Cornell Legal Information Institute: Treasury Regulation 301.7503-1 (weekend and holiday rule)
- IPX1031 (Investment Property Exchange Services): 1031 exchange days calculator
Last reviewed October 2026 by Matthew Martinez.
