Time of Day - format.format - INVALID_FLD_VALUE - What am I missing?

Hello,

I have been attempting to write a time value to a "Time of Day" custom field using a suitelet. I have spent the last four hours working on it. All I have managed to do is get a different variation of the same error message. What do I need to do to write to a time of day field without getting an invalid_fld_value error?

I have matched the company and user preferences as per SuiteAnswers Answer Id: 44671.

Here is the most promising code example, that still failed:

 //the time variable is milliseconds as a string  ftime =  format.format({                  value: new Date(parseInt(time)),                  type: format.Type.TIMEOFDAY              });  time_punch.setValue({                      fieldId: 'custrecord_punch_in_time',                      value: ftime                  });  time_punch.save();