Hi Costa,
Query 1 : If the property "WeatherForecast.Date" does not rename, for example, to "WeatherForecast.ForecastDate" an error occurs.
We have validated the reported issue and we considered this as a bug in our end. We have created a defect report for “Throws script error while setting input element with ID value as Date in Blazor” and the fix will be included in our patch release which is expected to be rolled out on January 21, 2020.
You can track the status of the reported issue from the below feedback link.
Query 2 : If the regional format of the computer is different from the US (for example, German), an error occurs (If the day is more than 12).
We have considered the reported issue ("While define the format against the loaded culture, error class will be added to the input element") as a bug at our end and this fix will be included in our upcoming bi-weekly release which is expected to be rolled out on or before 14th January 2020. We appreciate your patience until then.
You can track the status of the reported issue from the below feedback link.
Please get back to us if you need further assistance.
Regards,
Renjith Singh Rajendran.