I know that I can use this for the start of the month moment().startOf('month') but I need the first Sunday of the month.
You could do this:
function getFirstWeekDay(dateString, dayOfWeek) {
var date = moment(dateString, "YYYY-MM-DD");
var day = date.day();
var diffDays = 0;
if (day > dayOfWeek) {
diffDays = 7 - (day - dayOfWeek);
} else {
diffDays = dayOfWeek - day
}
console.log(date.add(diffDays, 'day').format("YYYY-MM-DD"));
}
//Pass in the first of a given calendar month and the day weekday
getFirstWeekDay("2016-10-01", 0);
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