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'  && Number(sampleActivity)>0 ) {
      if(Math.ceil(Math.log(MODERN_ACTIVITY/Number(sampleActivity))/(0.693/HALF_LIFE_PERIOD))<0) return false;
      return Math.ceil(Math.log(MODERN_ACTIVITY/Number(sampleActivity))/(0.693/HALF_LIFE_PERIOD));
    }
    return false;
  };
  