Invalid format (return structure): Property Name 'Fldate', Property Value '00000000'

Hi Experts,

I have developed a simple ODATA services where i want to read and update data in sflight table. I am able to read the data and i use "use as request" option and change fldate value and click on POST then i get the error

Invalid format (return structure): Property Name 'Fldate',  Property Value '00000000'

I am not sure how to enter the date value. I have tried yyyymmdd, dd.mm.yyyy etc., but nothing seems to work. see the attached image.

thanks