Please find the below sample code for which describe how to setup selectorformat property value programmatically. In the below code, wcf service is used and communicated to progress request/response mechanism. Use this as sample model towards your requirements and this works out now.
SelectorFormat = "H/M/T". This can be customized as per the requirements as "h or H", "M or m" or "T or t".
Please find the below source code for much better idea towards this.