DICOM DateTime Format
The Standard DICOM DateTime Format
The standard DateTime format (YYYYMMDD) is explained in Table 6.2-1 of Part 5 of the DICOM standard.
What Format DicomObjects Accepts
DicomObjects takes String format as well as DateTime format and turns whatever dates it is given into DICOM dates, according to the Regional Settings of the machine DicomObjects is running on, so on a European machine the value "04/03/2007" will be 20070304 in DICOM format and on a US machine it will produce 20070403.