QS:Date max
From LimeSurvey Manual
Maximum date (date_max)
Description
This question attribute can be used to set the maximum value for the date question (in y-m-d format or any other English valid string - see below for more options). It can be used for both popup and dropdown display options.
Attention : The Expression Manager validation option can also be used for setting up a "maximum date". However, if you use the popup calendar and the expression relies on a previous question located on the same page, the year will not be displayed correctly in the popup calendar.
Valid values
- Any date value in format YYYY-MM-DD (eg., 2018-08-24);
- Any year value;
- Any English string : "now", "-10 years", "tomorrow";
- Reference to another date/time question : AnotherDateQuestion (using the question code);
- Expressions: With expressions, a date can be dynamically calculated. For example, you can use a date from a previous answer + 3 days as a maximum date for the present question by entering: date("Y-m-d",strtotime(departuredate)+3*60*60*24).