Ontario offer deadline calculator
Condition periods and irrevocable dates, counted every way practice counts them, with Ontario statutory holidays built in. It will not tell you your deadline. It will show you the arithmetic and flag the days where two reasonable people would land on different answers.
Enter the acceptance, get every reading
Everything runs in your browser. Nothing is sent anywhere, which matters because these are live deal dates.
The agreement
Use the date the last party signed back, not the date the offer was drafted. That is the acceptance date the count runs from.
Every way of counting
Because Ontario does not have one
The counting rule is not a fact you can look up. It is whatever your clause says, read against a convention that is not written down anywhere binding.
If a deal is accepted Thursday and the condition runs five days, is Friday day one or is Thursday? Excluding the acceptance day is the more common reading, and it is still a reading. Two agents on the same deal can count to different Tuesdays.
A clause that says "business days" without defining them leaves open whether that means weekdays, or weekdays minus statutory holidays, or minus bank closures. The safest clause names the actual date and skips the argument entirely.
The Civic Holiday on the first Monday of August is not a public holiday under the Employment Standards Act. Most offices close; the law does not require it. So it is shown separately here rather than folded in.
Ontario statutory holidays used by this tool:
Dashed outline marks the Civic Holiday, which is observed but not a statutory public holiday.
What this tool will not do
It will not tell you your deadline, because your clause does that and we have not read it. It does the arithmetic, which is the part that is genuinely annoying, and it shows you where the conventions disagree, which is the part worth knowing before you rely on a date.
If all four readings land on the same day, you can stop thinking about it. If they do not, that gap is your risk, and the fix is not a better calculator - it is writing the actual calendar date into the clause so nobody has to count at all. Where money or a firm deal turns on it, that is a question for the lawyer on the file, not for a web page.
Once the clock is running
Counting the date is the easy half. Remembering it three weeks later, across nine live deals, is the half that loses deposits.