The string format works because when using a JSON based data source the values are all strings. There are a couple of options to work around this and I have listed them below.
Option 1 (Recommended)
Use the built in Parameters Area to set parameters for the report and data source. I have attached a sample project that displays how to do this and provided additional information below.
This method will require converting the date formats using the provided Conversion Functions. For example, if the report parameter is in the DateTime format. The Web Service Query would look like the following screenshot. Doing this will convert the parameter value to a string format which matches the API input parameter.
Additionally, it will require converting the string formats to the desired value and setting the format properties in the report. See below screenshots for more information.
The Table TextBox Properties:
Convert the DateTime parameter to a Date prior to passing the parameter to the report. More information is available at the Converting string to Date Stack Overflow thread.
To test the attached sample, I recommend setting up the Telerik NugetFeed in Visual Studio.
Please let me know if you need any additional information. Thank you for using Telerik Reporting.
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