Update readme to detail how to load calendars

README.md

@@ -15,70 +15,73 @@ $ gem install business
 
 ### Getting started
 
-Get started with business by creating an instance of the calendar class,
-passing in a hash that specifies with days of the week are considered working
-days, and which days are holidays.
+Get started with business by creating an instance of the calendar class, passing in a hash that specifies with days of the week are considered working days, and which days are holidays.
 
 ```ruby
 calendar = Business::Calendar.new(
   working_days: %w( mon tue wed thu fri ),
   holidays: ["01/01/2014", "03/01/2014"]    # array items are either parseable date strings, or real Date objects
+  extra_working_dates: [nil], # Makes the calendar to consider a weekend day as a working day.
 )
 ```
 
-`extra_working_dates` key makes the calendar to consider a weekend day as a working day.
+### Load a calendar from a file
 
-A few calendar configs are bundled with the gem (see [lib/business/data]((lib/business/data)) for
-details). Load them by calling the `load` class method on `Calendar`. The
-`load_cached` variant of this method caches the calendars by name after loading
-them, to avoid reading and parsing the config file multiple times.
+#### Calendar file definition
 
-```ruby
-calendar = Business::Calendar.load("weekdays")
-calendar = Business::Calendar.load_cached("weekdays")
-```
+Defining a calendar as a Ruby object may not be convient, to load it from a YAML file follow and customise the example below. All keys are optional and will default to the following:
+
+- If `working_days` is missing, then common default is used (mon-fri).
+- If `holidays` is missing, "no holidays" assumed.
+- If `extra_working_dates` is missing, then no changes in `working_days` will happen.
 
-If `working_days` is missing, then common default is used (mon-fri).
-If `holidays` is missing, "no holidays" assumed.
-If `extra_working_dates` is missing, then no changes in `working_days` will happen.
+> Note: Elements of `holidays` and `extra_working_dates` may be eiter strings that `Date.parse()` can understand, or YYYY-MM-DD (which is considered as a Date by Ruby YAML itself).
 
-Elements of `holidays` and `extra_working_dates` may be
-eiter strings that `Date.parse()` can understand,
-or YYYY-MM-DD (which is considered as a Date by Ruby YAML itself).
+#### Example
 
 ```yaml
+working_days:
+  - Monday
+  - Wednesday
+  - Friday
 holidays:
-  - 2017-01-08  # Same as January 8th, 2017
+  - 1st April 2020
+  - 2021-04-01
+extra_working_dates:
+  - 9th March 2020 # A Saturday
 ```
 
-### Checking for business days
+#### Using the calendar
 
-To check whether a given date is a business day (falls on one of the specified
-working days or working dates, and is not a holiday), use the `business_day?`
-method on `Calendar`.
+Ensure the calendar file is saved to a directory that will hold all your calendars, eg; `path/to/your/calendar/directory` then add this directory to your code before you call your calendar:
 
 ```ruby
-calendar.business_day?(Date.parse("Monday, 9 June 2014"))
-# => true
-calendar.business_day?(Date.parse("Sunday, 8 June 2014"))
-# => false
+Business::Calendar.load_paths = ["path/to/your/calendar/directory"]
 ```
 
-### Custom calendars
-
-To use a calendar you've written yourself, you need to add the directory it's
-stored in as an additional calendar load path:
+Now you can load the calendar by calling the `load` class method on `Business::Calendar`. The
+`load_cached` variant of this method caches the calendars by name after loading them, to avoid reading and parsing the config file multiple times.
 
 ```ruby
-Business::Calendar.additional_load_paths = ['path/to/your/calendar/directory']
+calendar = Business::Calendar.load("my_calendars")
+# or
+calendar = Business::Calendar.load_cached("my_calendars")
 ```
 
-You can then load the calendar as normal.
+### Checking for business days
+
+To check whether a given date is a business day (falls on one of the specified working days or working dates, and is not a holiday), use the `business_day?` method on `Business::Calendar`.
+
+```ruby
+calendar.business_day?(Date.parse("Monday, 9 June 2014"))
+# => true
+calendar.business_day?(Date.parse("Sunday, 8 June 2014"))
+# => false
+```
 
 ### Business day arithmetic
 
-The `add_business_days` and `subtract_business_days` are used to perform
-business day arithmetic on dates.
+The `add_business_days` and `subtract_business_days` are used to perform business day arithmetic on dates.
 
 ```ruby
 date = Date.parse("Thursday, 12 June 2014")
@@ -88,10 +91,7 @@ calendar.subtract_business_days(date, 4).strftime("%A, %d %B %Y")
 # => "Friday, 06 June 2014"
 ```
 
-The `roll_forward` and `roll_backward` methods snap a date to a nearby business
-day. If provided with a business day, they will return that date. Otherwise,
-they will advance (forward for `roll_forward` and backward for `roll_backward`)
-until a business day is found.
+The `roll_forward` and `roll_backward` methods snap a date to a nearby business day. If provided with a business day, they will return that date. Otherwise, they will advance (forward for `roll_forward` and backward for `roll_backward`) until a business day is found.
 
 ```ruby
 date = Date.parse("Saturday, 14 June 2014")
@@ -101,51 +101,24 @@ calendar.roll_backward(date).strftime("%A, %d %B %Y")
 # => "Friday, 13 June 2014"
 ```
 
-To count the number of business days between two dates, pass the dates to
-`business_days_between`. This method counts from start of the first date to
-start of the second date. So, assuming no holidays, there would be two business
-days between a Monday and a Wednesday.
+To count the number of business days between two dates, pass the dates to `business_days_between`. This method counts from start of the first date to start of the second date. So, assuming no holidays, there would be two business days between a Monday and a Wednesday.
 
 ```ruby
 date = Date.parse("Saturday, 14 June 2014")
 calendar.business_days_between(date, date + 7)
 # => 5
 ```
 
-### Included Calendars
+## But other libraries already do this
 
-We include some calendar data with this Gem but give no guarantees of its
-accuracy.
-The calendars that we include are:
+Another gem, [business_time](https://github.com/bokmann/business_time), also exists for this purpose. We previously used business_time, but encountered several issues that prompted us to start business.
 
-* Bacs
-* Bankgirot
-* BECS (Australia)
-* BECSNZ (New Zealand)
-* PAD (Canada)
-* Betalingsservice
-* Target (SEPA)
-* TargetFrance (SEPA + French bank holidays)
-* US Banking (ACH)
+Firstly, business_time works by monkey-patching `Date`, `Time`, and `FixNum`. While this enables syntax like `Time.now + 1.business_day`, it means that all configuration has to be global. GoCardless handles payments across several geographies, so being able to work with multiple working-day calendars is
+essential for us. Business provides a simple `Calendar` class, that is initialized with a configuration that specifies which days of the week are considered to be working days, and which dates are holidays.
 
-## But other libraries already do this
+Secondly, business_time supports calculations on times as well as dates. For our purposes, date-based calculations are sufficient. Supporting time-based calculations as well makes the code significantly more complex. We chose to avoid this extra complexity by sticking solely to date-based mathematics.
 
-Another gem, [business_time](https://github.com/bokmann/business_time), also
-exists for this purpose. We previously used business_time, but encountered
-several issues that prompted us to start business.
-
-Firstly, business_time works by monkey-patching `Date`, `Time`, and `FixNum`.
-While this enables syntax like `Time.now + 1.business_day`, it means that all
-configuration has to be global. GoCardless handles payments across several
-geographies, so being able to work with multiple working-day calendars is
-essential for us. Business provides a simple `Calendar` class, that is
-initialized with a configuration that specifies which days of the week are
-considered to be working days, and which dates are holidays.
-
-Secondly, business_time supports calculations on times as well as dates. For
-our purposes, date-based calculations are sufficient. Supporting time-based
-calculations as well makes the code significantly more complex. We chose to
-avoid this extra complexity by sticking solely to date-based mathematics.
+---
 
 
 ![I'm late for business](http://3.bp.blogspot.com/-aq4iOz2OZzs/Ty8xaQwMhtI/AAAAAAAABrM/-vn4tcRA9-4/s1600/daily-morning-awesomeness-243.jpeg)