Using SET to insert a DateAndTime value into a mib

Using SET to insert a DateAndTime value into a mib

Hi,
 I am trying to update a leaf node which takes a value of type DateAndTime. I have tried several format but I keep getting:

Request Failed: Get Response PDU received from 10.0.10.7 Error Indication in response: The value given has wrong type or length. Errindex: 1


2012-12-05,17:59:03.0
2012-12-05,17:59:03
'2012-12-05,17:59:03.0 '
' 2012-12-05,17:59:03'  and various other formats.
Am I doing something wrong? Is there a limitation on the SET functionality in the Mib browser?