Bradley T. Borden (Brooklyn; Google Scholar), Like-Kind Exchange Deadlines That Fall on Weekends and Holidays, 181 Tax Notes Fed. 261 (Oct. 9, 2023):

In this article, Borden examines several court decisions that have extended section 7503 deadlines to the next business day, and he argues that the same extension applies to the deadlines under section 1031 for like-kind exchanges of property.

The Predicament
Every so often, exchangers find themselves in a predicament that raises the question whether the section 1031 45-day identification and 180-day exchange periods can be extended if they fall on a weekend or holiday.

For example, an exchanger may be prepared to close the acquisition of replacement property on a Friday that is one day before the Saturday end of the 180-day exchange period. Through no fault of the exchanger, the acquisition may not close on that Friday but on the following Monday. In that situation, the exchanger hopes there is authority to report the acquisition of the replacement property as occurring within the exchange period. In fact, the law appears to extend section 1031 deadlines that fall on a weekend or holiday to the next business day. …

Conclusion
Courts apply section 7503 and similar principles to non-procedural acts, so section 7503 appears to apply to the section 1031 deadlines. Although that application may not arise frequently, exchangers, their advisers, and section 1031 QIs should still be familiar with it and understand how it can affect the tax consequences of an exchange.m