Forty-five days is roughly a month and a half — six weeks and three days. Unlike 14 or 28, it is not a whole number of weeks, so the end date lands on a different weekday than today. It appears most often in real estate, insurance, and contract deadlines, where the 45-day mark is written into the rules.
The 45-day rule in a 1031 exchange
The best-known 45-day deadline in the US is the identification period in a Section 1031 like-kind exchange. After selling an investment property, an investor has exactly 45 calendar days to identify replacement properties in writing, and 180 days total to close on one.
Critical details investors get wrong:
- The 45 days are calendar days, including weekends and federal holidays
- The clock starts the day after the sale closes
- There is no extension for a deadline landing on a weekend
- Missing the 45-day identification window disqualifies the exchange and triggers capital gains tax
Because the consequences are financial and irreversible, exchange deadlines are worth confirming with your qualified intermediary rather than a calculator alone.
Other 45-day deadlines
Forty-five days recurs across contracts and consumer protection:
- Insurance: many states require claim decisions within 45 days of proof of loss
- Credit disputes: card issuers must resolve certain billing disputes within set windows measured in days, not months
- Employment: severance agreements offered to a group carry a 45-day review period under US age-discrimination rules
- Contracts: 45-day cancellation and renewal-notice windows are common in service agreements
- Returns: extended holiday return policies often run 45 days
Frequently Asked Questions
How many weeks is 45 days?
Six weeks and three days. Since 45 is not a multiple of seven, the end date falls three weekdays later than your starting weekday — 45 days from a Monday lands on a Thursday.
Does the 45-day 1031 exchange deadline include weekends?
Yes. The identification period is 45 calendar days including weekends and holidays, and it is not extended if the final day falls on a weekend. The clock starts the day after your relinquished property closes, and the full exchange must close within 180 days.
How many business days are in 45 calendar days?
Between 31 and 33 business days, assuming a Monday–Friday week and no public holidays. The exact figure depends on which weekday you start from: 45 days spans either six weekends (33 weekdays) or seven (31 weekdays). The live figure above is calculated for today’s actual start date.