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@HomerJSimpson
Last active September 28, 2022 22:14
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Calculate Second Monday of the month in javascript (not quite done)
/*jslint plusplus:true, white:true */
/*global console:false */
function secondMonday(year, month) { "use strict";
var firstDay = new Date(year, month, 1);
if(firstDay.getDay() !== 1) {
firstDay.setDate(
firstDay.getDay() === 0 ? 2 : 9 - firstDay.getDay()
);
}
firstDay.setDate(firstDay.getDate() + 7);
return firstDay;
}
var year, month;
for(year=2017;year>2013;--year) {
for(month=0;month<12;++month) {
console.log(secondMonday(year, 11-month) + "\n");
}
}
@heymartinadams
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Hey @KevDev99 haven’t verified it (and don’t have the brainpower to do so at the moment — too busy with other stuff), but I’ll take your word for it! Thank you ✨

@heymartinadams
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heymartinadams commented Sep 28, 2022

Had to do another calculation for last [weekday] of the month (e.g. last Sunday of August 2022) — as opposed to first, second, etc. Hat tip to @brucemcpherson for this snippet and to Dennis R. for this snippet:

let year = 2022, month = 7, ordinal = 'last', weekday = 'Sun'

let d

const dayOfWeek = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'].findIndex(x => x === weekday)

// Get the date of the last weekday: e.g. ordinal = 'last', weekday = 'Tue' of the month
if (ordinal === 'last') {
  // Last day of desired month
  d = new Date(year + (month.getMonth() === 11 ? 1 : 0), (month.getMonth() + 1) % 12, 0)

  d.setUTCHours(0, 0, 0, 0)

  // Find out what day of week that is and adjust
  d.setUTCDate(d.getUTCDate() - ((d.getUTCDay() + 7 - dayOfWeek) % 7)) // Note difference btw `getDate()` and `getDay()`

  console.log(ordinal, weekday, d)
}

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