The library is the collection of all common functionalities for: date, day, week, month

- Date functions:

+ get min / max date in the input list

+ get position of min / max date in the input list

- Date time functions:

+ get millisecond difference by 2 input date times

+ get UTC date time by input date time

- Day functions:

+ get weekend day difference between 2 input dates

+ get working day difference between 2 input dates

- Month functions:

+ get first day of month by input date / week number

+ get last day of month by input date / week number

- Week functions:

+ get week difference between 2 input dates

+ get day of week by input date

+ get Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday by the input date / week number

+ week number by input date