#include <StringConstants.au3> ; to declare the Constants of StringRegExp
#include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate
Local $sRegex = "(?m)^(((\d{4}\/((0[13578]\/|1[02]\/)(0[1-9]|[12]\d|3[01])|(0[13456789]\/|1[012]\/)(0[1-9]|[12]\d|30)|02\/(0[1-9]|1\d|2[0-8])))|((([02468][048]|[13579][26])00|\d{2}([13579][26]|0[48]|[2468][048])))\/02\/29)){0,10}$"
Local $sString = "2016-02-29" & @CRLF & _
"2019/12/31" & @CRLF & _
"" & @CRLF & _
"29/02/2016" & @CRLF & _
"" & @CRLF & _
"^(?:(?:31(\/|-|\.)(?:0?[13578]|1[02]))\1|(?:(?:29|30)(\/|-|\.)(?:0?[1,3-9]|1[0-2])\2))(?:(?:1[6-9]|[2-9]\d)?\d{2})$|^(?:29(\/|-|\.)0?2\3(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00))))$|^(?:0?[1-9]|1\d|2[0-8])(\/|-|\.)(?:(?:0?[1-9])|(?:1[0-2]))\4(?:(?:1[6-9]|[2-9]\d)?\d{2})$" & @CRLF & _
"" & @CRLF & _
"^(((\d{4}-((0[13578]-|1[02]-)(0[1-9]|[12]\d|3[01])|(0[13456789]-|1[012]-)(0[1-9]|[12]\d|30)|02-(0[1-9]|1\d|2[0-8])))|((([02468][048]|[13579][26])00|\d{2}([13579][26]|0[48]|[2468][048])))-02-29)){0,10}$"
Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH)
Local $aFullArray[0]
For $i = 0 To UBound($aArray) -1
_ArrayConcatenate($aFullArray, $aArray[$i])
Next
$aArray = $aFullArray
; Present the entire match result
_ArrayDisplay($aArray, "Result")
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm