Ý nghĩa của ngày tháng

7 days in week were named after 5 stars, the Sun and the Moon. They also symbolize 7 elements in chemistry.
+ Monday- the Moon- Silver
+ Tuesday- the Mars- Iron
+ Wednesday- the Mercury- Mercury
+ Thursday- the Jupiter- Zinc
+ Friday- the Venus- Copper
+ Saturday- the Saturn- Lead
+ Sunday- the Sun- Gold