Maximum time() | PHP

Question

It's kind of a silly question, but what would be the maximum INT value of a time() and it's future date, e.g.

1st January 2999

Would time() ever get to that value? Going for a large time() value would return this:

Thu 1st Jan 1970 1:00AM

A normal int date

1287320788 - outputs today's date: Sun 17th Oct 2010 2:06PM

But I'm only curious for the biggest int date and the last date.

Solution 1

The last 32-Bit Integer timestamp will be reached January 19, 2038. This is known as the Year 2038 problem.

Solution 2

PHP stores the highest integer number it can represent in the PHP_INT_MAX constant:

date('Y-m-d H:i:s', PHP_INT_MAX); // 2038-01-19 04:14:07

If you want to work with dates beyond that, consider using the DateTime API, e.g.

$dt = new DateTime('1st January 2999');
$dt->add(DateInterval::createFromDateString('+1 day'));
echo $dt->format('Y-m-d H:i:s'); // 2999-01-02 00:00:00
echo $dt->format('U');           // 32472226800

Solution 3

Remember, the Y2038 problem does not apply on 64-bit systems.

Solution 4

The shortest way I know is to get tomorrow's date:

date("Y-n-j", strtotime("+1 day"))

date("Y-n-j", PHP_INT_MAX) on 64bit-systems gives potential dangerous value: 292277026596-12-4

Solution 5

On 64-bit platforms PHP_INT_MAX does not reflect maximum INT value for 32-bit platforms. Here's how to get it:

$max32bitInt = PHP_INT_SIZE == 4 ? PHP_INT_MAX : PHP_INT_MAX>>32;

If you're always using 64-bit platform, just use:

PHP_INT_MAX>>32

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Comments

[Wrikken]

For MySQL, see also stackoverflow.com/questions/2012589/…

[Pekka]

That link also has good background info on the PHP side

[Florian Müller]

Has that been fixed recently in PHP's time()? The biggest value it can make to a date is now 9223372036854772207 (04.12.292277026596 15:30:07) (very close to the 64 Bit Integer max value)

[Pekka]

Yup, using DateTime and - on mySQL side - the DATETIME field type fixes the issue completely.

[MacMac]

Thanks for this Pekka. Will this ever be solved once we nearly reach to it?

[Pekka]

@YouBook if PHP still exists by then, probably. It's going to be easy to fix by switching the underlying system to larger INTs - Won't be much of a problem thanks to PHP's weak typing. Alternatively, use DateTime as suggested by Gordon

[Pekka]

Mmm, are you sure? Will PHP's internal handling of integers turn to 64-bit automatically?

[oglgo]

I'm not exactly sure, but it seems to roll over on my box... :-)

[Jonah]

64-bit will be okay for the next ~300 billion years.

[Westy92]

Be careful. The Y2038 problem always applies on Windows systems. "64-bit platforms usually have a maximum value of about 9E18, except for Windows, which is always 32 bit." php.net/manual/en/language.types.integer.php

[Tomasz Kapłoński]

Basically the problem will solve itself by definition since 2038 is max int in 32-bit system and most computers are already 64-bit which means waaaay more range in terms of integers...

[Christian]

Well if I remember correctly, XAMPP on Window still uses 32 bit integers even on 64 bit machines.