// JS getDay() index: 0=Sunday .. 6=Saturday
export const DOW = ['周日', '周一', '周二', '周三', '周四', '周五', '周六']

// BYDAY codes indexed by JS getDay(): DOW_EN[getDay()] => 'SU'..'SA'
export const DOW_EN = ['SU', 'MO', 'TU', 'WE', 'TH', 'FR', 'SA']

export const BYDAY_TO_INDEX = { SU: 0, MO: 1, TU: 2, WE: 3, TH: 4, FR: 5, SA: 6 }

/** Return the BYDAY code ('SU'..'SA') for a JS Date. */
export function bydayFromDate(date) {
  return DOW_EN[date.getDay()]
}

/** Return the Chinese weekday label for a JS Date. */
export function dowLabel(date) {
  return DOW[date.getDay()]
}