From the web api reference here I tried querying the api with no luck of success specially with the parameter Schedules being stated as type string. 1.) For msdyn_BookingResource POST: https://bhaud365dev.crm6.dynamics.com/api/data/v9.0/msdyn_BookingResource BODY: {"ResourceId":[GUID],"BookingStatusId":[GUID],"BookingMethod":690970003,"BookingType":1,"Schedules":"[{\"StartDateTime\":\"2019-07-15T00:00:00Z\",\"EndDateTime\":\"2019-07-19T00:00:00Z\"}]","Timeframe":5} RESPONSE: { "error": { "code": "0x80040224", "message": "The added or subtracted value results in an un-representable DateTime.\r\nParameter [...] read more