faustf,
Roll your own...
Local $mon = MonthtoNumber('jan')
ConsoleWrite((@error ? '! Error >>> ' & @error : $mon) & @CRLF)
Func MonthtoNumber($str)
If Not StringIsAlpha($str) Then Return SetError(1, 0, $str)
If StringLen($str) < 3 Then Return SetError(2, 0, $str)
Local $aMonths = ['january', 'february', 'march', 'april', 'may', 'june', 'july', 'august', 'september', 'october', 'november', 'december']
For $i = 0 To UBound($aMonths) - 1
If StringInStr($aMonths[$i], $str) Then Return $i + 1
Next
Return SetError(3, 0, $str)
EndFunc ;==>MonthtoNumber
kylomas