Hi Scott,
Thank you for your interest in Syncfusion products.
The mask format “Mask="##/##/#### ##:##” in the MaskedEditControl just displays the given input value in DateTime format. So, we suggest you to use DateTimeTextBox for assigning 24 hour time format.
This can be set by using the following code,
[C#]
DateTimeTextBox1.Format = DateTimeFormatType.CustomString;
DateTimeTextBox1.CustomFormat = "MM/dd/yyyy HH:mm:ss:ff tt"; //HH:mm:ss:ff tt denotes the 24 hour time format
Kindly refer the following link to know more information on TimeFormat in DateTimeTextBox.
http://help.syncfusion.com/ug_84/User%20Interface/ASP.NET/Tools/Documents/dateandtimeformat.htmPlease let me know if this helps,
Regards,
Varalakshmi.R.S