text: const CustomError = require("../extensions/custom-error");
  
  const MODERN_ACTIVITY = 15;
  const HALF_LIFE_PERIOD = 5730;
  
  module.exports = function dateSample(sampleActivity) {
  
    if ((typeof (sampleActivity) !== 'string')) {
      return false;
    }
  
    if (isNaN(parseInt(sampleActivity))) {
      return false;
    }
  
    if ((sampleActivity <= 0) || (sampleActivity > 15)) {
      return false;
    }
  
    return Math.ceil(MODERN_ACTIVITY / sampleActivity) / (0.693 / HALF_LIFE_PERIOD);
  
  };
  