Specified cast not valid for datetime while using SAP RFC

When working with SAP RFC connections in .NET applications, you may encounter the "Specified cast not valid for datetime" error. This typically occurs when trying to convert SAP date/time formats to .NET DateTime objects due to format mismatches.

Understanding the Issue

SAP systems often use different date and time formats than what .NET expects by default. The most common SAP date format is dd.mm.yyyy or variations with time components. When .NET tries to automatically parse these values, it fails because it cannot recognize the format.

Solution Using ParseExact Method

The best approach is to use the ParseExact method available in the DateTime type. This method allows you to specify the exact format of your date string, ensuring proper conversion.

Example

Please find the code snippet for reference ?

using System;
using System.Globalization;

class Program
{
    static void Main()
    {
        string argumentDate = "25.12.2023 14:30:45";
        string dateFormat = "dd.MM.yyyy HH:mm:ss";
        
        DateTime finalDate = DateTime.ParseExact(argumentDate, dateFormat, CultureInfo.InvariantCulture);
        
        Console.WriteLine("Original SAP date: " + argumentDate);
        Console.WriteLine("Parsed DateTime: " + finalDate.ToString());
    }
}

The output of the above code is ?

Original SAP date: 25.12.2023 14:30:45
Parsed DateTime: 12/25/2023 2:30:45 PM

Key Points to Remember

When using ParseExact, ensure that ?

• The format string exactly matches your SAP date format
• Use MM for months (not mm which represents minutes)
• Use HH for 24-hour format or hh for 12-hour format
• Always use CultureInfo.InvariantCulture to avoid locale-specific parsing issues

Conclusion

Using DateTime.ParseExact with the correct format string and CultureInfo.InvariantCulture effectively resolves the "Specified cast not valid for datetime" error when working with SAP RFC date conversions.