@gameroom/cli/src/extensions/Date.js

A command line tool for Gameroom

const PERIOD_START = 1598763600000 // Aug 30, 2020
const DAYS = [ 'Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday' ]
// static methods
Date.beginningOfDay = (d) => {
  d = d ? new Date(d) : new Date()
  d.setHours(0,0,0,0)
  return d
}
Date.beginningOfYesterday = (d) => {
  d = d ? new Date(d) : new Date()
  d.setHours(0,0,0,0)
  d.addDays(-1)
  return d
}
Date.beginningOfWeek = (d) => {
  d = d ? new Date(d) : new Date()
  const day = d.getDay()
  const diff = d.getDate() - day + (day === 0 ? -7 : 0)
  const result = new Date(d.setDate(diff))
  result.setHours(0,0,0,0)
  return result
}
Date.endOfWeek = (d) => {
  d = d ? new Date(d) : new Date()
  if (d.getDay()) d = Date.beginningOfWeek(d)
  return d.addDays(7)
}
Date.beginningOfPeriod = (d) => {
  d = d ? new Date(d) : new Date()
  d.setHours(0,0,0,0)
  d.setDate(d.getDate() - d.getDay()) // Sunday
  let period = new Date(PERIOD_START)
  while (period <= d) period.addDays(14)
  while (period > d) period.addDays(-14)
  return period
}
Date.endOfPeriod = (d) => {
  d = d ? new Date(d) : new Date()
  let period = Date.beginningOfPeriod(d)
  while (period <= d) period.addDays(14)
  return period
}
Date.beginningOfMonth = (d) => {
  d = d ? new Date(d) : new Date()
  return new Date(d.getFullYear(), d.getMonth(), 1)
}
Date.fromSeconds = (s) => new Date(s * 1000)
// instance methods
Date.prototype.addHours = function (d) {
  this.setHours(this.setHours() + d)
  return this
}
Date.prototype.addDays = function (d) {
  this.setDate(this.getDate() + d)
  return this
}
Date.prototype.withDays = function (d) {
  const date = new Date(this)
  return date.addDays(d)
}
Date.prototype.getDayOfWeek = function () {
  return DAYS[this.getDay()]
}