MyFeatureContext.php

<?php
use Behat\Behat\Context\BehatContext;

class MyFeatureContext extends BehatContext {
	
	protected $dateFormat = 'Y-m-d';

	/**
	 * Transforms relative date statements compatible with strtotime().
	 * Example: "date 2 days ago" might return "2013-10-10" if its currently 
	 * the 12th of October 2013. Customize through {@link setDateFormat()}.
	 * 
	 * @Transform /^(?:(the|a)) date of (?<val>.*)$/
	 */
	public function castRelativeToAbsoluteDate($prefix, $val) {
		$timestamp = strtotime($val);
		if(!$timestamp) {
			throw new \InvalidArgumentException(sprintf(
				"Can't resolve '%s' into a valid datetime value",
				$val
			));
		}
		return date($this->dateFormat, $timestamp);
	}

	public function getDateFormat() {
		return $this->dateFormat;
	}

	public function setDateFormat($format) {
		$this->dateFormat = $format;
	}
}