PHP strtotime returning false for UTC time

Question

My colleague and I are obtaining different results from some unit tests that use strtotime.

The discrepancy originates in this line:

$value = strtotime('2050-05-01T20:10:29.410Z');

on my machine, this result returns the following:

int(2535048629)

whereas my colleague's version returns false

We are both using PHP version 5.4.14 and PHPUnit 3.724.

Has anyone got any idea what is causing this discrepancy, and is there a more robust approach?

Answer 1

This is because he is on 32-bit and you are on 64-bit machine. See what echo PHP_INT_MAX; returns on both machines. More read here.

If you wish to get timestamp on 32-bit machine, you can use DateTime as:

$value = new DateTime('2050-05-01T20:10:29.410Z');
echo $value->format('U');  // returns 2535048629 as string

or format inputed timestamp as:

$value = new DateTime('@2535048629');
echo $value->format('r'); // Sun, 01 May 2050 20:10:29 +0000

instead of date('r', '2535048629'); which will not work on 32-bit machine.

Answer 2

It's likely related to 32-bit vs 64-bit. Timestamps in the year 2050 are larger than 32 bits.