Currently $dateFromParts will handle appropriately a day that's bigger than largest day in the specified month (i.e. year:2017, month:2, day:30 correctly becomes "2017-03-02" since there are only 28 days in February) but if day is >31 it gives an error. Same for month>12.
”‘day’ must evaluate to an integer in the range 1 to 31, found 32"
Instead it should just construct appropriate date (so 2017, 2, 32 is "2017-03-03" and 2017 month 13 is January of 2018. This allows simple construction of dates that are X days after given date or Y months after given date, etc.