function getOffsetToWeekOrigin(day, offsetWeek = 0) {
  let offset = day >= offsetWeek ? day - offsetWeek : 7 + day - offsetWeek;
  offset = offset === 0 ? 7 : offset // if the two days collide, we force 7 days padding
  return offset
}
@export
@param {any} day , first day of current month, 0 - 6
@param {number} [offsetWeek=0, 0-6, 0 sunday, 6 saturday] 
@returns