解决PHP的date函数"YW"参数自然周BUG

官方的文档是记录了这个bug的，只会在计算1年的第一周和最后一周会有错误。 Things to be aware of when using week numbers with years. <?php echo date("YW", strtotime("2011-01-07")); // gives 201101 echo date("YW", strtotime("2011-12-31")); // gives 201152 echo date("YW", strtotime("2011-01-01")); // gives 201152 too 这里就会有问题 ?> BUT <?php echo date("oW", strtotime("2011-01-07")); // gives 201101 echo date("oW", strtotime("2011-12-31")); // gives 201152 echo date("oW", strtotime("2011-01-01")); // gives 201052 (Year is different than previous example) ?> Reason: Y is year from the date o is ISO-8601 year number W is ISO-8601 week number of year Conclusion: if using 'W' for the week number use 'o' for the year. 找php手册帮忙http://www.php.net/manual/zh/function.date.php 里面就有详细介绍 要注意哦！