A decade duration is 10 years
1 decade equals 120 months, or 3650 days or 87600 hours.
The word is derived from the Greek: δεκάς, romanized: dekas. It means means a group of ten. A decade may describe any period of ten years. For example a period of time in a person’s life, or describe specific groups of calendar years. Officially in 1950, the decade became a part of the English vocabulary. The significance of a decade is that it refers to 10 years in the previous years.
The use of decades to symbolize ten years period has enabled humanity to distinguish significant historical events. Many of the historical happenings are grouped in decades. These groupings made it easier for people to differentiate events that happened during a particular time in previous years.
Any event that repeats every decade is referred to as a decennial event. Likewise, events that happen every 100 years and 1000 years are considered centennial and millennial events, respectively.