Three Periods, 60 Minutes: How the Hockey Clock Works

A standard ice hockey game has three regulation periods. In the Olympic format described by the IOC, each period lasts 20 minutes, producing 60 minutes of regulation game-clock play, with an intermission after the first and second periods (Olympic ice hockey competition procedure). If the score is tied, overtime or a shootout may follow under the competition’s rules, but that extra play is not a fourth regulation period.

The short answer: hockey has three regulation periods

For the NHL, the regulation structure is also three periods of 20 minutes each, according to this guide to periods in hockey. The basic timeline is:

Period 1 (20 minutes) → intermission → Period 2 (20 minutes) → intermission → Period 3 (20 minutes)

Three periods of 20 minutes add up to 60 minutes on the game clock. Because the breaks occur only between periods, regulation contains two intermissions, not three.

The word regulation matters. Every game using this format begins with three scheduled regulation periods, but that does not mean every game ends after exactly three periods of play. If the score remains tied and the applicable competition requires a winner, the game may continue into overtime. Depending on the rules, a shootout may follow as a separate tie-breaking procedure.

It is therefore useful to separate three related ideas:

• Regulation periods: the three scheduled periods that make up the main game
• Overtime periods: additional timed play after a regulation tie
• Shootout: individual scoring attempts used to break a tie, rather than another timed period

This distinction prevents a common misunderstanding: a game can contain more than three timed periods without overtime becoming part of regulation.

Why 60 minutes of hockey takes longer than one hour

The 60-minute figure measures regulation time on the game clock. It does not measure the total time that passes from the opening faceoff to the end of the event.

The game clock does not simply run for 20 uninterrupted minutes during each period. When officials stop play, the clock stops as well. Play then resumes with time still remaining in the period.

Intermissions add more elapsed time. There is one after the first period and another after the second. These breaks give the teams time away from the ice and commonly provide an opportunity for the playing surface to be resurfaced before the next period begins.

There is no single intermission duration that applies to every form of hockey. The Olympic reference cited above describes 15-minute intermissions, while the official format for the 2026 IIHF women’s Olympic tournament specifies 18-minute intermissions (IIHF tournament format). Those figures belong to their respective competition descriptions and should not be turned into a universal rule.

A game’s elapsed duration can therefore include:

• 60 minutes of regulation game-clock play
• Two intermissions
• Stoppages while the game clock is not running
• Overtime, if the score is tied and the rules require additional play
• A shootout, if the applicable tie-breaking format calls for one

The first three items are enough to make a regulation game last longer than one hour in real time. Overtime and a shootout can extend it further. Because stoppages and extra play are not identical from game to game, there is no fixed real-world finishing time that applies across hockey.

Does overtime count as a fourth period?

No. Overtime is separate from the three regulation periods and should not be called a fourth regulation period. It begins only after regulation ends tied and only when the competition’s rules call for additional play or require a winner.

The following formats are NHL-specific, based on the NHL procedures described in the cited hockey period and overtime guide. They should not be assumed to apply to Olympic, international, youth, recreational or amateur games.

Stage	When it applies	Format	Regulation?
Regulation	Every NHL game	Three 20-minute periods	Yes
NHL regular-season overtime	Tied after regulation	One five-minute, three-on-three sudden-death period	No
NHL playoff overtime	Playoff game tied after regulation	Successive 20-minute sudden-death periods	No
Shootout	Regular-season game still tied after overtime	Individual scoring attempts without a period clock	No

In sudden-death overtime, the game ends as soon as a team scores. An NHL regular-season overtime period is scheduled for up to five minutes, but it can finish earlier if a goal is scored. Under the described format, a regular-season game that remains tied after overtime proceeds to a shootout.

NHL playoff overtime follows a different structure. Each overtime period is scheduled for up to 20 minutes, but the period and the game end immediately when either team scores. If no goal is scored before that overtime period expires, another sudden-death period follows. There is no predetermined maximum number of overtime periods in this format.

A shootout is not a hockey period. It does not consist of continuous, timed team play. Instead, players take individual attempts under a separate tie-breaking procedure. Calling it a “shootout period” would therefore blur the distinction between timed play and the mechanism used to decide the winner.

Because overtime rules can change and differ by context, anyone who needs the exact applicable procedure should consult the competition’s current official rules or game information.

Which timing rules vary by league and playing level?

The three-period structure is standard in the NHL and in the cited Olympic formats. The Olympic reference also applies that basic structure to the sport’s competition procedure, while the cited 2026 women’s tournament format likewise uses three 20-minute periods. The evidence therefore supports the structure in both men’s and women’s Olympic hockey without implying that every tournament uses identical overtime or intermission rules.

Outside those settings, exact timing can vary. The relevant league or tournament rules—not the NHL format—determine the duration for a particular game.

Several details may change between competitions:

• The length of each regulation period
• The duration of each intermission
• The length and number of possible overtime periods
• The number of skaters used during overtime
• Whether overtime ends immediately after a goal
• Whether a shootout follows overtime
• Whether a tie can remain in the final result
• Whether preliminary-round, playoff and medal-round games use different procedures

Even within one league, regular-season and playoff formats can differ substantially. The NHL examples show this clearly: the described regular-season format uses one short three-on-three overtime before a possible shootout, while playoff games use successive sudden-death overtime periods.

Tournament stages can also matter. A preliminary-round procedure should not automatically be assumed to govern a medal game, and a format published for one Olympic tournament should not be presented as the rule for every IIHF event.

For casual viewing, the practical expectation is straightforward: anticipate three regulation periods and two intermissions. For transportation, broadcasting, coaching or tournament administration, check the current rulebook or official game information for the specific league, age group, event and stage.

How hockey arrived at three periods

Hockey was not always organized into three periods. The NHL’s official historical record dates the change from two 30-minute periods to three 20-minute periods to the 1910–11 season. It also records that, in 1927–28, the game was standardized as three 20-minute periods of stop time separated by intermissions.

For standard professional and the cited Olympic/IIHF formats today, the usable rule is simple: expect three regulation periods and 60 minutes on the game clock. If the score is tied, extra play may follow, but overtime, shootout and lower-level timing procedures depend on the competition.