Translations:Question type - Date/28/en
From LimeSurvey Manual
Dates in Limesurvey are saved as a string (text format). The ExpressionScript converts all dates part of an expression into the standard format "yyyy-mm-dd HH:MM:SS". This makes it much easier to compare dates in an expression (e.g. "date1>date2"). If you need a datestring in the format it was asked in the question, use the ".shown" attribute (e.g.: You were born on the {birthdate.shown}.)