"Bulfinch's Mythology is a collection of the works of Thomas Bulfinch, renamed after him and published after his death. It is a classic work of mythology and is still being printed, even 150 years after the first work, Age of Fable, was published in 1855." (Wikipedia)
Perhaps the oldest written story on Earth, this epic comes from Ancient Sumeria and was originally written on 12 clay tablets in cunieform script. It is about the adventures of the historical King of Uruk (somewhere between 2750 and 2500 BCE).
This site, from the Minneapolis Institute of Arts, gives an example of an artistic work from each of 4 different Native American cultures and explains the story behind the mythological elements in the works.
This outline gives meanings of the days of the week in English, Latin, and sometimes Greek, and explains the origins of those names from Greek, Roman, and Norse gods and concepts. Note that the Spanish names for the days of the week are derived from Latin.
This summary gives the meanings of the names of the months of the year, in English as derived from Latin and Greek. Please note that the Spanish names for the months comes from the Latin. Note that some of these names have to do with mythology, some with numbering the months, and some with Roman leaders.