In general dates and times are handled correctly by the objects in this collection, all necessary conversions being performed.  This means that:

• DICOM dates are received in both the old (YYYY/MM/DD) and new (YYYYMMDD) format, the same applying to time and date/time values also.
• The value of an correctly formatted DicomAttribute of DICOM value representation DA, TM or DT is a Variant of type Date.
• When creating an element of a date related type using DicomAttributes.Add, either a date variant, or any type that Windows can coerce into a date is acceptable, and will be correctly converted.

There is, however, an anomaly in the DICOM standard, allowing dates and times to contain ‘range’ values in the forms ‘value-value’ ‘-value’ or ‘value-‘.  Such constructs are not easily handled by the mechanisms above, and therefore, in order to allow such values to be used in queries (both outgoing and incoming), any date or time value which cannot be recognised will normally be stored and passed on as a simple string.

Applications creating such ranges will need to create them directly in a form such as   ‘19810101-19811231’, and they may also be interpreted this way if required, but as of version 4.1, DicomObjects provides the DateTimeFrom and DateTimeTo properties, which simplify this process for programmers writing SCPs.