Hi Montenegr0,
If I understand your question, if you are only interested in 'time' and not 'date', all you need to do is change the KIND property of the datetimepicker field to 'time' (the default is 'date') (see screenshot).
If you want to use both DATE and TIME, I find it easiest to use 2 fields, one to store the date (with KIND property defaulting to 'date') and one to store the time (with KIND property set to 'time).
If you want the date and time showing in the same field, I still use 2 fields and link them using the CALENDAR property of the datetimepicker field. It would be much easier if you could do this all in the same field but if it is possible, I don't know of a way to do it.
Derek.