Working as a zookeeper requires you to be passionate about animals and wildlife conservation. You often spend more time with the animals than other zoo employees, getting to know their habits and personalities. This helps you determine when the animals are healthy or whether they need veterinary care, a vital role of primary caregivers.
So on average the number of days between two similar phases (e.g. between one full moon and the next full moon) is about 29.531 days. This period is referred to as a lunation, lunar month, or synodic month.
A Blue moon is attributed to an extra full moon in the season, so the fourth Full moon of a season is a Blue moon since there are usually only three. There are 12.37 Full moons in a year, so a Blue moon must occur on average every 2.7 years.