How Limitation Periods Are Counted (Accrual, Tolling, Discovery)

A limitation period looks like arithmetic: a claim has "three years," so add three years and you have the deadline. In practice the hard question is almost always when the clock started. Four rules stack: accrual sets day zero, a discovery rule can move day zero later, tolling can pause a clock already running, and a statute of repose can kill the claim regardless of all three. Whether a particular claim is timely needs a lawyer; the statutes below are examples of drafting, not a survey.

Accrual: day zero is a legal question, not a calendar one

The period runs from the date the cause of action accrues — often not the day the defendant did something wrong.

• Breach of contract generally accrues at breach, not at signature and not when the injured party notices; it is complete even if no loss has been felt yet.
• Negligence normally accrues when damage occurs, since damage is an element of the tort. Careless conduct that has caused nothing yet starts no clock.
• Instalment obligations accrue separately for each missed payment. Part payment or a signed written acknowledgement can restart the whole period — sections 29 and 30 of the Limitation Act 1980 in England and Wales — which is why a "dead" debt revives after one small payment.
• Continuing wrongs such as an ongoing nuisance can accrue afresh each day, so limitation governs how far back you can recover, not whether you can sue.
• Demand obligations split by jurisdiction. UCC § 3-118(b) gives six years after demand on a demand note, and bars it if neither principal nor interest is paid for a continuous ten years. Other systems treat a demand debt as accruing when the money is handed over.

The arithmetic is the easy part. Two lawyers can agree the period is six years and still be years apart on the deadline.

The discovery rule is not a default, and not everywhere

A discovery rule moves the start date to when the claimant knew — or reasonably should have known — of the injury and its cause. The second half is what gets litigated: it is an objective standard, so the clock can start before the claimant understood anything, if a reasonable person would have investigated. An unexplained diagnosis or a survey flagging a defect can be that trigger.

Scope varies far more than general accounts suggest:

• England and Wales runs an alternative three-year period from the date of knowledge for latent damage in negligence (Limitation Act 1980, s.14A), capped by a fifteen-year longstop from the negligent act or omission (s.14B).
• US federal securities fraud claims run two years from discovery of the violation's facts, and no later than five years from the violation (28 U.S.C. § 1658(b)).
• Maine's Law Court has confined the discovery rule to a short list — legal malpractice, foreign-object and negligent-diagnosis medical malpractice, and asbestosis — so most Maine clocks run from injury whether anyone knew or not.
• Ordinary contract claims often get no discovery rule at all, which catches out anyone assuming "I only just found out" helps.

Check what "discovery" means in the provision. Some statutes require knowledge of the injury only; others also its cause and the defendant's identity — a gap worth years.

Tolling pauses a running clock — it does not reset it

When the condition ends, the clock resumes where it stopped; elapsed time is not given back. A three-year period that ran eight months, tolled two years, then resumed leaves two years and four months. Grounds vary:

• Minority. Periods commonly do not run against a child. Under s.28 of the Limitation Act 1980 the clock starts at 18, so a three-year injury claim arising at age 6 expires at 21.
• Legal incapacity preventing a person from managing their own affairs, sometimes for as long as it lasts.
• Fraudulent concealment. Distinct from the discovery rule: it turns on the defendant's active concealment, not the claimant's ignorance.
• Defendant's absence. Several US states toll while the defendant is out of state or not amenable to service.
• Agreed tolling. These are contracts; the wording controls whether it suspends the clock or grants a fixed extension.
• Procedural suspension — a bankruptcy stay, a mandatory pre-action process, a court-ordered emergency suspension.

Statutes of repose: the outer wall

A repose period runs from a fixed external event — substantial completion, first sale, the professional act — and expires on schedule regardless of accrual, discovery, or usually tolling. California's CCP § 337.15 is a clean example: ten years from substantial completion for property damage from latent construction defects, carved out only for willful misconduct and concealment.

They run in parallel and repose wins: a claim discovered last month with three years of limitation left is dead if repose has run.

Lengths vary — check yours rather than assuming

These examples illustrate the spread; none is the law where you are.

Watch the last row: missing a government notice deadline ends the claim while the limitation period is still running.

Counting the last day

• Exclude day zero. Federal Rule of Civil Procedure 6(a)(1)(A) excludes the day of the triggering event and counts every day after, so a three-year period accruing 12 March 2024 lands on 12 March 2027. Some provisions produce the day before; calendar the earlier date.
• 29 February has no anniversary. A period accruing 29 February 2024 has no matching date in 2025, 2026 or 2027. Some rules resolve to 28 February, others to 1 March, and day-count statutes sidestep it — see our leap years and date math pitfalls guide.
• The last day rolls forward. Under FRCP 6(a)(1)(C) a deadline falling on a Saturday, Sunday or legal holiday runs to the next day that is none of those, on the court's holiday calendar rather than the bank one.
• Closing time is not automatically midnight. FRCP 6(a)(4) ends the last day at midnight in the court's time zone for electronic filing, but when the clerk's office closes for other filing methods. Local rules differ; the portal's behaviour is not the rule.

Treat the calculated date as a hard internal deadline and file well before it. Rollover is a defence of last resort, not a plan.

For the arithmetic: days between two dates measures elapsed time from an accrual date, 36 months from today projects a three-year horizon, and 30 business days from today covers rules written in business days — see our guide to counting business days. Where minority tolling applies, the age calculator gives the date a claimant turns 18.