XaviJr

# September 20, 2012 at 7:35 am

So this is my code:

$birth = ‘1994-09-18′;
$birth_minus_100 = date(‘Y-m-d’, strtotime(‘- 100 year’, strtotime($birth)));

It work fine when I substract 2 years or so, with 100 the result is 1970-01-01. It seems to me some PHP bug no?

Adrianc333

# September 20, 2012 at 8:09 am

A timestamp is the number of seconds elapsed since January, 1st, 1970.
So any date before then won’t exist (in timestamp terms)

You should use a different date/time format for going back that far.

__

# September 20, 2012 at 8:45 pm

Use the DateTime class.

You shouldn’t have a problem unless you need to go back more than 292 billion years. : )

To answer your question about it being a “bug,” no, it’s not a bug. It’s a known limitation with unix timestamps, and it’s not specific to PHP.