When does the 1031 exchange clock start?

Both periods begin on the date you transfer the relinquished property (Treas. Reg. §1.1031(k)-1(b)(2)). Counting that date as day 0, the identification period ends at midnight on day 45 and the exchange period at midnight on day 180 — calendar days after the transfer. Selling more than one property in the same exchange? Both periods run from the EARLIEST transfer (Treas. Reg. §1.1031(k)-1(b)(2)(iii)).

Are 1031 deadlines calendar days or business days?

Calendar days. Weekends and holidays count. The IRS does not extend deadlines that land on a Saturday, Sunday, or federal holiday — except through IRS disaster relief under §7508A (federally declared disasters, significant fires, terroristic or military actions).

Can a 1031 deadline be extended?

Only when the IRS postpones deadlines under IRC §7508A for taxpayers affected by a federally declared disaster, a significant fire, or a terroristic or military action, and its relief notice covers 1031 deadlines (Rev. Proc. 2018-58, section 17). The 45- and 180-day deadlines then move by 120 days or to the end of the general relief period, whichever is later, but never past the due date (including extensions) of your return for the year of the sale or one year. There is no extension for personal hardship, broker delay, or financing problems. Separately, if day 180 falls after your return's due date, filing a timely return extension (Form 4868 or 7004) keeps the full 180 days; it doesn't add days beyond day 180 (IRC §1031(a)(3)(B)).

What happens if I close on December 1?

For an individual filing Form 1040, the 180-day deadline (May 30 the following year, or May 29 when that February has 29 days — a Dec 1, 2027 closing ends May 29, 2028) extends past the return's April 15 due date. The exchange period ends on the EARLIER of day 180 or your return's due date INCLUDING extensions — so file Form 4868 and you keep the full 180 days; skip it and the exchange period is cut short to April 15 (the due date, regardless of when you actually file). This is the most common 1031 timing mistake.

Does it matter whether I or my LLC or partnership owns the property?

Yes. The 180-day period is also capped by the due date of the return that reports the sale. An individual or single-member LLC (Form 1040) has an April 15 due date and extends with Form 4868. A partnership or multi-member LLC (Form 1065) or S corporation (Form 1120-S) on a calendar year has a March 15 due date (IRC §6072(b)) and extends with Form 7004, so any closing after September 16 (September 17 when the following February has 29 days) needs that extension to keep the full 180 days. C corporations, trusts and estates file by the 15th day of the 4th month after the tax year ends and also extend with Form 7004.

How does the 45-day identification rule work?

By midnight of day 45 you must sign a written identification of the replacement property and deliver it to the seller of the replacement property, or to someone else involved in the exchange who is not you and not a "disqualified person" — usually your Qualified Intermediary, an escrow agent or a title company. Your own attorney, accountant, real-estate agent or broker, or employee who has worked for you in the past two years (other than on 1031 exchanges or routine title, escrow or bank services), and related parties, are disqualified (Treas. Reg. §1.1031(k)-1(c)(2), (k)). You can identify up to (a) three properties of any value (3-property rule), or (b) any number whose total fair market value is ≤200% of the relinquished property (200% rule).

1031 Exchange

1031 Exchange Timeline Calculator

Calculate your 45-day identification and 180-day closing deadlines from the relinquishment closing date.

Updated August 24, 2026Reviewed for 2026 tax yearIRS-sourcedReviewed by Adam Khale

Two deadlines control every 1031 exchange and missing either by even one calendar day disqualifies the entire deferral. This calculator implements IRC §1031(a)(3) and Treas. Reg. §1.1031(k)-1(b) — counting calendar days from your relinquishment closing date (day 0).

Day extensions granted outside disaster relief

About Our Editorial Process

How are 1031 exchange deadlines calculated?

The 45-day identification window and 180-day exchange window are CALENDAR days counted from the relinquishment closing date (day 0). Weekends and holidays count. The only extension comes from IRS disaster relief under §7508A and Rev. Proc. 2018-58. Separately, if day 180 falls after your return's due date, filing a timely return extension (Form 4868 or 7004) keeps the full 180 days; it doesn't add days beyond day 180.

•Day 0 = closing date of relinquished property (the earliest one, if you sell several)
•Day 45 = identification deadline (signed list to QI)
•Day 180 = exchange deadline (replacement closes)
•Individuals closing after about Oct 17, and calendar-year partnerships and S corps closing after about Sept 16 (one day later when the following February has 29 days): extend the return (Form 4868 / Form 7004) to keep the full 180 days. The calculator shows your exact date.

Read Full 1031 Guide

The 1031 timeline isn't negotiable. The IRS doesn't care about holidays, the qualified intermediary going on vacation, or the title company taking three weeks. 45 days to identify, 180 days to close — calendar days, not business days, counted from the day the sale closes.

Real-world scenario

Investor sold a $600K rental Jan 15, 2026, found nothing by Mar 1

Day 0: Jan 15, 2026 closing. Day 45: Mar 1 (Feb 29 in a leap year such as 2028) — must have written identification of up to 3 replacement properties (or use the 200% rule). Investor was traveling, identified nothing. The exchange collapses. The $200K gain is taxable that year: say $80K of it is depreciation taken (unrecaptured §1250 gain, taxed at up to 25%, about $20K) and $120K is appreciation (15%, about $18K) — roughly $38K federal before the 3.8% net investment income tax and state tax, all of which a completed exchange would have deferred.

The part most people miss

The 'three-property rule' isn't a limit — it's a default. You can identify unlimited properties under the 200% rule (total FMV ≤ 200% of relinquished property value) or the 95% rule (must close on 95% of identified value). Sophisticated exchangers identify 5-7 backup properties on Day 44; rookies identify one and pray.

Relinquishment property closing date

This is "day 0" — the date your relinquished property's deed transferred to the buyer. Selling more than one property in the same exchange? Enter the EARLIEST closing: both deadlines run from the first transfer (Treas. Reg. §1.1031(k)-1(b)(2)(iii)).

Who owns the relinquished property (whose return reports the sale)?

The 180 days are also capped by the due date of this return: April 15 for Form 1040, March 15 for a calendar-year Form 1065 or 1120-S, and the 15th day of the 4th month after the tax year ends for Forms 1120 and 1041 (IRC §6072).

45-Day Identification

Thursday, October 8, 2026

Submit signed identification of up to 3 replacement properties (or use the 200% rule) to your Qualified Intermediary by midnight.

180-Day Exchange

Saturday, February 20, 2027

Close on identified replacement property by midnight. Outer limit — your return's due date (with extensions) can cut it shorter; see the exchange deadline below.

Falls on a weekend — close earlier to be safe.

Timeline Summary

Day 0 — Relinquishment closingMonday, August 24, 2026

Day 45 — Identification deadlineThursday, October 8, 2026

Day 180 — outer exchange limitSaturday, February 20, 2027

Exchange deadlineSaturday, February 20, 2027

How the Counting Rules Work

•Day 0: Closing date of the relinquished property (deed transfer). With several relinquished properties in one exchange, use the EARLIEST closing (Treas. Reg. §1.1031(k)-1(b)(2)(iii)).
•Day 1: The calendar day immediately after closing. Counting begins here.
•Calendar days, not business days. Weekends, holidays, leap days — all count.
•No grace period. Unlike most IRS deadlines, weekend/holiday deadlines do NOT roll forward for 1031 exchanges.
•Disaster relief: Only IRS relief under §7508A (federally declared disasters, significant fires, terroristic or military actions), applied to 1031 deadlines by Rev. Proc. 2018-58.

1031 Tax-Deferral Calculator

Estimate capital-gains and recapture tax deferred

1031 Exchange Guide

Full rules, identification methods, boot, QI requirements

Sources & References

Primary references used for this content

Form 8824

Like-Kind Exchanges

§1031 reporting, boot, and deferred gain

View on irs.gov

IRC §1031

Exchange of real property held for productive use

Like-kind exchange requirements and timelines

View on law.cornell.edu

✓2 primary sources; links re-checked on a weekly rotation by the source watcher

Disclaimer: This calculator provides estimates for educational purposes only. Not tax, legal, or financial advice. Results may vary based on your specific circumstances. Consult a qualified CPA or tax professional for personalized guidance.