ts-days-between-two-dates
Problem Statement
Calculate weekdays and business days between two dates.
Task One: Weekdays Between Two Dates
Calculates the number of weekdays in between two dates.
- Weekdays are Monday, Tuesday, Wednesday, Thursday, Friday.
- The returned count should not include either firstDate or secondDate - e.g. between Monday 07-Oct-2013 and Wednesday 09-Oct-2013 is one weekday.
- If secondDate is equal to or before firstDate, return 0. Expected Results The following scenarios will allow you to validate your application is working as expected: |Start Date | End Date | Result |7th October 2013 | 9th October 2013 | 1 |5th October 2013 | 14th October 2013 | 5 |7th October 2013 | 1st January 2014 | 61 |7th October 2013 | 5th October 2013 | 0
Task Two: Business Days Between Two Dates
Calculate the number of business days in between two dates.
- Business days are Monday, Tuesday, Wednesday, Thursday, Friday, but excluding any dates which appear in the supplied list of public holidays.
- The returned count should not include either firstDate or secondDate - e.g. between Monday 07-Oct-2013 and Wednesday 09-Oct-2013 is one weekday.
- If secondDate is equal to or before firstDate, return 0. Expected Results Sample list of Public Holidays:
- 25th December 2013
- 26th December 2013
- 1st January 2014 Given those public holidays, the following scenarios will allow you to validate your application is working as expected: | Start Date | End Date | Result | 7th October 2013 | 9th October 2013 | 1 | 24th December 2013 | 27th December 2013 | 0 | 7th October 2013 | 1st January 2014 | 59
Task Three: More Holidays
Design a data structure or hierarchy of structures which can define public holidays in a more complex fashion than simple dates. This should cater for things such as:
- Public holidays which are always on the same day, e.g. Anzac Day on April 25th every year.
- Public holidays which are always on the same day, except when that falls on a weekend. e.g. New Year's Day on January 1st every year, unless that is a Saturday or Sunday, in which case the holiday is the next Monday.
- Public holidays on a certain occurrence of a certain day in a month. e.g. Queen's Birthday on the second Monday in June every year. Given this data structure, the BusinessDaysBetweenTwoDates() function should be able to be extended to take a list of public holiday rules, rather than a list of DateTimes, and calculate the number of business days between two dates using those rules to define public holidays.
Solution
Class Structure
HolidayType
- FixedHolidayType
- AdjustedHolidayType
- CertainDayHolidayType
PublicHolidays -> Data structure to manage all HolidayType days
Notes
- The code separates each type of holiday into its own class, this gives a single responsibility to each class. New holiday types can be easily added.
- The abstract base class HolidayType forces each derived class to implement the "isHoliday" function and enables different implementations.
- There is a separation of concerns into different classes to promote readability, testability, reusability and makes it easy to maintain and evolve.
- The PublicHolidays data structure behaves like a list which stores different types of holidays. Each holiday has a different type and specification (resources/holiday-data.json contains sample data).
- The following have been added to make sure the code is "production-ready":
- Unit test cases
- Linting using ESLint
- Code Formatting using Prettier
- The BusinessDayCounter class has been built to be used as an NPM package.
- npm install days-between-two-dates-utility
- Import and instantiate BusinessDayCounter
- Call functions with inputs
- weekdaysBetweenTwoDates(firstDate: Date, secondDate: Date)
- businessDaysBetweenTwoDates(firstDate: Date, secondDate: Date, publicHolidays: Date[])
- businessDaysBetweenTwoDatesUsingDS(firstDate: Date, secondDate: Date) (requires resources/holiday-data.json for holiday types input)