datevalue function takes a date as a text (or string) as input and returns outpu

wrap your text to your format first using text(<YOUR_VALUE>, "DD-MM-YYYY")

this works . but I don't see a function that validates a date (given input as string) for any formats like mm.dd.yyyy
for example datevalue("3.4.2012") - returns 1/4/2035 which is incorrect.
datevalue("22-Aug-2012") - returns 8/22/2012 which is perfect but datevalue("32-Aug-2012") returns "5/6/1153" which is incorrect . I see there are some gaps needs to get addressed in Date and Time functions

That's one of the reasons date shouldn't be from a free form text but from a date picker.

Agreed, date validation expression OOB would make it easy for getting dates from other systems.

validation expression OOB ?