It works using date("Y-m-d H:i") instead of date("Y-m-d").

The comparison fails at the moment because
[date from datepicker] =< date("Y-m-d")
i.e.
2015-03-27 00:00 =< 2015-03-27
is not true.

I also corrected a mistake in the wiki concerning date_max

Added some code to enhance comparison and avoid errors like I got.

PR: https://github.com/LimeSurvey/LimeSurvey/pull/298
Commit: https://github.com/LimeSurvey/LimeSurvey/commit/4b7f15e4a1c6596c72a2cb69d67688d6ce748efe

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&amp;id=15062

Fix committed to master branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&amp;id=15063

PR for v2.06: https://github.com/LimeSurvey/LimeSurvey/pull/299
Commit: https://github.com/gabrieljenik/LimeSurvey/commit/2d6849a8ae267c4868bde63fd01561169c03bd94

Fix committed to 2.06 branch: http://bugs.limesurvey.org/plugin.php?page=Source/view&amp;id=15065

The change breaks usage of certain EM conditions for min/max values.

For example it was previously possible to use

Maximum date: date('Y-m-d')+1

Now this condition does not validate properly.
This needs to be fixed urgently.

I do not know what LS produced with "date('Y-m-d')+1", but it is not a valid expression. Date() produces a string in the given format and "+1" likely adds a "1" to the string. A correct expression to allow for dates up to tomorrow would be: date("Y-m-d H:i", strtotime("now")+606024). But maybe there are other ways.

You are right - sorry, can be closed again.

I am reopening this to make some comments about previous notes.

When adding a date question, date_min and date_max are attributes that are said to handle expressions, as << date('Y-m-d') + 1 >>.

As now, inside the code, those expression are taken as a parameter by strtotime, and I guess that generates an error.

So my guess the issue is valid... what do you think?
To solve the issue I would almost revert the change: Remove the strtotime from there.

PS: The expression to allow dates up to tomorrow could also be << date("Y-m-d H:i", strtotime("tomorrow")) >>. That put into an LS question configuration (after this issue is solved) could be something like date_max: << strtotime("tomorrow") >>

Gabrieljenik: The error comes because date('Y-m-d') + 1 is not a valid expression because it would be like adding "1" to the string "2015-04-22". The expression "date("Y-m-d H:i", strtotime("now")+606024)" works well.

Entering strtotime("tomorrow") will not work for two reasons:
1) We're using phpjs to have strtotime available in javascript for same page calculation/validation. The implementation in the phpjs library is not complete and strtotime("tomorrow") is not supported.

2) In the datemin/max field you need to enter a valid dateSTRING such as "2015-04-22" or "22.04.2015" or an expression that will produce such a string. Strtotime will produce the number of seconds since 1970, so this needs further conversion via function date().

Sorry, you are right.