How long are hockey periods?

Hockey periods are divided into several parts, Here is in detail have a detailed look:
NHL and Professional Leagues – 20 minutes each.
Junior or Amateur Leagues – Often 15 to 20 minutes, depending on the level.
Overtime – 5 minutes in the regular season (3-on-3), 20 minutes in playoffs (5-on-5).
Intermissions – Usually 15-18 minutes between periods for rest and ice resurfacing.
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