Still in process but it's already usible, see tests for usage examples

Moment Weekday Calculator plugin

This plugin will count specific weekdays in the range.

Usage

Count all weekdays in the range:
moment().weekdayCalc('1 Apr 2015','31 Mar 2016',[0,1,2,3,4,5,6]); //366, here Sunday is 0
moment().isoWeekdayCalc('1 Apr 2015','31 Mar 2016',[1,2,3,4,5,6,7]); //366, here Sunday is 7
please notice that weekdays in the array must be integers, NOT strings like '1', '2'

Count all Monday to Friday workdays of 2015-2016 financial year:
moment().weekdayCalc('1 Apr 2015','31 Mar 2016',[1,2,3,4,5]); //262
moment().isoWeekdayCalc('1 Apr 2015','31 Mar 2016',[1,2,3,4,5]); //262

Count all Mondays and Tuesdays of 2015 calendar year:
moment('2015').weekdayCalc([1,2]); //104
moment('2015').isoWeekdayCalc([1,2]); //104

Count all Fridays in the range:
moment('14 Feb 2014').weekdayCalc('23 Feb 2014',[5]); //2
moment('14 Feb 2014').isoWeekdayCalc('23 Feb 2014',[5]); //2

Node "Standalone" usage (it is not actually standalone, just uses moment as inner dependency):
WeekDayCalc = require('moment-weekday-calc);
var useIsoWeekdays = true;
var calc = new WeekDayCalc('1 Jan 2015', '31 Dec 2015', [1,2,3,4,5,6,7], useIsoWeekdays);
var result = calc.calculate(); //365

#Installation

##NPM npm install moment-weekday-calc

##Bower bower install moment-weekday-calc

Syntax

iso weekdays weekdayCalc

Calculate specified weekdays for dates range:
moment().isoWeekdayCalc(rangeStart moment|Date|String, rangeEnd moment|Date|String, weekdays Array);

Calculate specified weekdays for dates range:
moment(rangeStart moment|Date|String).weekdayCalc(rangeEnd moment|Date|String, weekdays Array);

Calculate specified weekdays for the whole current calendar year:
moment().isoWeekdayCalc(weekdays Array);

rangeStart - the range start

rangeEnd - the range end

weekdays - array of iso weekdays as integers to count [1, 2, 3, 4, 5, 6, 7], 1 is always Monday 7 is always Sunday

locale aware weekdayCalc

Calculate specified weekdays for dates range:
moment().weekdayCalc(rangeStart moment|Date|String, rangeEnd moment|Date|String, weekdays Array);

Calculate specified weekdays for dates range:
moment(rangeStart moment|Date|String).weekdayCalc(rangeEnd moment|Date|String, weekdays Array);

Calculate specified weekdays for the whole current calendar year:
moment().weekdayCalc(weekdays Array);

rangeStart - the range start

rangeEnd - the range end

weekdays - array of locale aware weekday numbers as integers, for example [1, 2, 3] please notice that range may be 1-7 or 0-6 depending on locale, Sunday may be 0 or 7, depending on locale, monday is usualy 1

Please be aware that you may receive unexpected results if you use weekdays not matching your locale, for example, if your locale weekdays range is 0-6:
moment().weekdayCalc('1 Jan 2015','31 Dec 2015',[1,2,3,4,5,6,7]);// returns 364
It happens because 7 here is a 'next monday', not sunday, and the last 'next' monday is out of the range, so one day of the year is not properly counted. Please visit http://momentjs.com/docs/#/get-set/weekday/ for reference.