PHP：将年份转换为月份和月份日期

Question

If you have the day of the year. How can you convert that to day of month and month? For example: The day "144" should be converted to 26th of May. I guess I also have to add the actual year to account for leap years. But I haven't found anything at all.

For example the function mktime() exepects the month, year and day of month.

Anybody some suggestions?

Answer 1

The most reliable and convenient way is to use the DateTime object. You can use DateTime::createFromFormat() static method to create it based on day in the current year:

$date = DateTime::createFromFormat('z', '144');

And because you know have DateTime object in the $date variable, you can perform literally any task you want to. To output the contained date, simply call:

echo $date->format('j. n. Y');

It will print out 24. 5. 2012, because it's leap year and because it indexes days starting from zero (just like array indices).

Answer 2

strtotime("January 1st +".($days-1)." days");

这将返回与一年中指定日期相对应的时间戳。