Question

What is the range of DateTime in PHP?

Even though the constructor does not seem to accept values in the Y-m-d format outside the [0-9999] range, the following works:

Adding 10.000 years:

// 12012-12-12
echo (new DateTime())->add(new DateInterval('P10000Y'))->format('Y-m-d');

Subtracting 10.000 years:

// -7988-12-12
echo (new DateTime())->sub(new DateInterval('P10000Y'))->format('Y-m-d');

I was unable to find this information in the documentation.

Answer 1

http://php.net/manual/en/intro.datetime.php

The date and time information is internally stored as a 64-bit number so all conceivably useful dates (including negative years) are supported. The range is from about 292 billion years in the past to the same in the future.