Hi Ereona,
You cannot get the date time unit selected by the scale, however you can change the value format that corresponds to a unit - for example:
someDateTimeScale.DateTimeUnitFormatterPairs.DayFormatter = new NDateTimeValueFormatter(DateTimeValueFormat.DateHour);
changes the default day formatting to day + hour. The other units have similar properties, SecondFormatter, MinuteFormatter etc.
Best Regards,
Nevron Support Team