text: const CustomError = require("../extensions/custom-error");
  
  const MODERN_ACTIVITY = 15;
  const HALF_LIFE_PERIOD = 5730;
  
  module.exports = function dateSample(sampleActivity) {
  	const activitiToFloat = parseFloat(sampleActivity);
  
  	if ((typeof (sampleActivity) == "string") && sampleActivity && (activitiToFloat > 0 && activitiToFloat < 15)) {
  		return Math.ceil((Math.log(MODERN_ACTIVITY / parseFloat(sampleActivity))) / (0.693 / HALF_LIFE_PERIOD));
  	}
  	else return false;
  
  
  }
  
  
  
  