All methods of the tvPoints object that use the time in their parameters or returned values, take real numbers with possible decimal part instead of time values.
It has sense only for trends that are not connected to data source (to a variable in the PmaTrendGroup object).
var oTView = pMe.Items("../TrendView");
var nType = oTView.TimeType; //reading
oTView.TimeType = 2; //writing