The timeunit element has three attributes, unit and devider and multiplier.
the unit is second, minute, hour, week, month year.
The divider attribute is optional (default = 1).
The timeZone (in decimal hours shift from GMT)
e.g. -1.0 or 3.5. If not present GMT is assumed
Type of data, either accumulative or instantaneous.
For accumulative data the time/date of the event is
the moment at which the data was gathered.