What you are looking for is parseFormat. format only accepts 1 value.
parseFormat is an array that
Specifies the formats, which are used to parse the value set with value() method or by direct input. If not set the value of the options.format and options.timeFormat will be used. Note that value of the format option is always used
Reference http://docs.kendoui.com/api/web/datetimepicker#configuration-parseFormats
and jsfiddle example
$("#sampleDate").kendoDatePicker({
format: "MM-dd-yyyy",
parseFormats: ["MM-dd-yyyy", "MM/dd/yyyy"]
});
the example will accept values in both the MM-dd-yyyy and MM/dd/yyyy and convert them to what is specified in format which is MM-dd-yyyy