Merge branch 'update/typedate_change' into 'master'

updating type Date

See merge request web-et-numerique/llle_project/self-data-technical-doc!1

docs/ecolyo/functionalities/challenge.md

@@ -50,7 +50,7 @@ Calculation of custom question is done by combination of all parameters:
 
 - If _period_ is empty.
 
-  Retrieve the **date** of day/month/year (define by _timeStep_) from the last week, month, year (define by _interval_).
+  Retrieve the **date** of day/month/year (define by _timeStep_) from the last week, month, year (define by _interval_), if there is no data in this interval, then it will go back to a previous interval, up to a maximum of 6 months
 
 ```
 example: What day did I consumme the most on the last week ?