Error 4835 when inserting an Event : Please check whether you have provided proper values for "DATE" fields

Error 4835 when inserting an Event : Please check whether you have provided proper values for "DATE" fields

Hi everyone,

      I'm currently trying to use the insertRecords method of the API to insert a new element in the Events module. But the API keeps returning me this error :
       4835: Please check whether you have provided proper values for "DATE" fields

And here is my xmlData: 
       <Events><row no="1"><FL val="Subject">Test</FL><FL val="Start DateTime">2015-08-26 02:19:00</FL><FL val="End DateTime">2016-08-26 05:10:00</FL><FL val="Event Owner">null</FL><FL val="Venue">null</FL><FL val="Who Id">null</FL><FL val="What Id">null</FL><FL val="Recurring Activity">null</FL><FL val="Created By">null</FL><FL val="Modified By">null</FL></row></Events>

      According to the error message, it looks like my "Start DateTime" and "End DateTime" have incorrect values. But the API's documentation clearly says : "Date & Time must be in yyyy-MM-dd HH:mm:ss format."

I'm running out of ideas to solve this so if anyone has some solution, I'm highly interested.

Thanks in advance