https://www.dss.gov.au/our-responsibilities/settlement-and-multicultural-affairs/programs-policy/a-multicultural-australia/government-building-social-cohesion/calendar-of-cultural-and-religious-dates
https://en.wikipedia.org/wiki/List_of_religions_and_spiritual_traditions
https://www.infoplease.com/world/religion/major-religions-world
Number 1 - Non religious holidays
http://www.sbs.com.au/news/article/2015/12/31/11-cultures-dont-celebrate-new-years-day-jan-1-0
http://www.un.org/en/ga/search/view_doc.asp?symbol=A/RES/70/193
http://www.un.org/en/sections/observances/international-years/
https://en.wikipedia.org/wiki/Burns_supper
http://www.officeholidays.com/countries/usa/index.php
http://www.officeholidays.com/countries/usa/mlk.php
https://www.timeanddate.com/holidays/uk/

Number 2 - Christianity
https://theway21stcentury.wordpress.com/2012/11/23/how-many-christian-denominations-worldwide/
https://en.wikipedia.org/wiki/List_of_Christian_denominations
https://www.catholicculture.org/culture/liturgicalyear/activities/view.cfm?id=993
https://en.wikipedia.org/wiki/Easter
https://en.wikipedia.org/wiki/Shrove_Tuesday
https://en.wikipedia.org/wiki/Feast_of_the_Ascension
https://en.wikipedia.org/wiki/Pentecost
https://en.wikipedia.org/wiki/Christmas
https://simple.wikipedia.org/wiki/Christianity

Number 3 - Hinduism
http://www.dummies.com/religion/hinduism/core-beliefs-of-hindus/
https://en.wikipedia.org/wiki/Hinduism
https://en.wikipedia.org/wiki/Atheism_in_Hinduism
https://en.wikipedia.org/wiki/Holi
https://en.wikipedia.org/wiki/Vishnu
https://en.wikipedia.org/wiki/Avatar
https://en.wikipedia.org/wiki/Krishna

Number 4 - Islam
https://simple.wikipedia.org/wiki/Islam
https://en.wikipedia.org/wiki/Abrahamic_religions
https://simple.wikipedia.org/wiki/Sunni_Islam
https://simple.wikipedia.org/wiki/Islam
https://en.wikipedia.org/wiki/Kaaba
https://en.wikipedia.org/wiki/Ramadan
https://en.wikipedia.org/wiki/Ramadan_(calendar_month)
https://en.wikipedia.org/wiki/Intercalation_(timekeeping)
https://en.wikipedia.org/wiki/Abraham

Number 5 - Judaism
https://simple.wikipedia.org/wiki/Judaism
https://en.wikipedia.org/wiki/Judaism
https://en.wikipedia.org/wiki/Yom_HaShoah
https://en.wikipedia.org/wiki/Israel
https://toriavey.com/what-is-shavuot/
https://en.wikipedia.org/wiki/Three_Pilgrimage_Festivals
https://en.wikipedia.org/wiki/Passover
https://en.wikipedia.org/wiki/Sukkot
http://www.chabad.org/holidays/JewishNewYear/template_cdo/aid/177886/jewish/What-Is-Yom-Kippur.htm