text: import interval from "./interval.js";
  import {durationWeek} from "./duration.js";
  
  function utcWeekday(i) {
    return interval(function(date) {
      date.setUTCDate(date.getUTCDate() - (date.getUTCDay() + 7 - i) % 7);
      date.setUTCHours(0, 0, 0, 0);
    }, function(date, step) {
      date.setUTCDate(date.getUTCDate() + step * 7);
    }, function(start, end) {
      return (end - start) / durationWeek;
    });
  }
  
  export var utcSunday = utcWeekday(0);
  export var utcMonday = utcWeekday(1);
  export var utcTuesday = utcWeekday(2);
  export var utcWednesday = utcWeekday(3);
  export var utcThursday = utcWeekday(4);
  export var utcFriday = utcWeekday(5);
  export var utcSaturday = utcWeekday(6);
  
  export var utcSundays = utcSunday.range;
  export var utcMondays = utcMonday.range;
  export var utcTuesdays = utcTuesday.range;
  export var utcWednesdays = utcWednesday.range;
  export var utcThursdays = utcThursday.range;
  export var utcFridays = utcFriday.range;
  export var utcSaturdays = utcSaturday.range;
  