Please accept this patch:

https://github.com/php/php-src/pull/615

I can confirm this behavior: <https://3v4l.org/HNaaY>.

> According to the documentation white space should be treated as
> invalid format and return false.

Where is this documented? That would actually be wrong; consider

  strtotime('2016-06-16 11:23')

which is supposed to be acceptable.

To cmb@php.net:

Obviously, invalid should be whitespace-ONLY arguments (in other words, becoming empty string after `trim()`), not arguments _containing_ whitespace.

'2016-06-16 11:23' does not become an empty (zero-length) string after trimming whitespace.

> Obviously, invalid should be whitespace-ONLY arguments (in other
> words, becoming empty string after `trim()`), not arguments
> _containing_ whitespace.

Indeed, thanks. However, where is this documented?

To cmb@php.net:

It looks like just common sense that whitespace is not a valid date or time — because it’s not a date, it’s…, well, whitespace. ;-)

The “Date Formats” page [1] does not mention whitespace at all, the “Time Formats” page [2] lists space (`[ \t]`) as a possible value, but I’m not sure it is not about just a non-self-contained _token_ intended to be a part of a full valid date/time string containing _not_ just whitespace.

Anyway, interpreting whitespace as a current date looks confusing, so this behavior probably deserves changing.

[1] http://php.net/manual/en/datetime.formats.date.php
[2] http://php.net/manual/en/datetime.formats.time.php

Thanks for pointing out the `space` time format. It does look like
to be intended to be a self-contained format, as several date
formats *contain* whitespace (for instance, `Textual month and
day`). And actually, that is quite contrary to what the reported
wrote.

> Anyway, interpreting whitespace as a current date looks
> confusing, so this behavior probably deserves changing.

I don't argue that accepting whitespace only as date time format
is rather doubtful, but as often is the case with *changes*, this
change would break BC. This is particularly bad, because the
whitespace has been documented to be allowed. So, in a strict
sense, this is not a bug. I'm changing to feature request.

Oops, disregard my former comment, since it is nonsense.

Anyhow, this is a duplicate of bug #66486.

I'm closing this (and the duplicate), as I am confused about this. Please open a new ticket at https://github.com/php/php-src/issues if this is still a pressing issue.